Caramelized Onion Ham and Cheese Sliders

A Fresh Take On The Classic French Onion Ham And Cheese Sliders

If you love the savory, rich flavors of onion, cheese, and ham, then these Caramelized Onion Ham and Cheese Sliders will be your new favorite dinner. Soft slider buns wrap around ham topped with melty American cheese and golden caramelized onions. A savory onion butter bakes into the buns to create the ultimate burst of flavor in every bite.

You know me, and you know I love a good canned soup or a good powdered packet. I am never going to be the person who tells you that everything needs to be made from scratch.

There is a time and a place for a packet of onion soup mix, and my kitchen has certainly seen its fair share of them.

But I recently got a bag of really beautiful Vidalia onions, and I wanted to use them for something where the onions would actually be the star.

That got me thinking about those classic baked ham and cheese sliders made with the buttery onion topping. There are lots of versions of them, and many use a packet of onion soup mix.

I started wondering if I could make something with that same familiar, savory onion flavor, but use actual caramelized onions instead.

The answer was yes.

These came out absolutely perfect.

I cooked the Vidalia onions low and slow until they were soft, sweet, and almost jammy. Most of the onions went inside the sandwiches with the ham and cheese, but I reserved a couple of tablespoons, minced them really fine, and stirred them right into the seasoned melted butter that goes over the tops of the buns.

You still get that buttery, savory, oniony flavor you expect from the classic sliders, but the caramelized onions give them a little something extra.

I used very thinly shaved ham off the bone and American cheese, which melted beautifully into the ham and onions.

I also changed things up with the bread.

You know I love me a Hawaiian roll. This is not me turning against Hawaiian rolls.

But for these I used a slightly larger, more traditional slider bun. You can see what I mean in the video in the recipe card. I liked having a little bit more substantial of a bun to hold all of the ham, cheese, and onions.

Hawaiian rolls would still work perfectly well if that is what you have or prefer.

Before You Jump To The Recipe

If you have a few minutes before heading to the recipe card, these sections will help you get the best results from these Caramelized Onion Ham and Cheese Sliders:

Why Vidalia Onions Are Perfect For These Sliders

How To Properly Caramelize The Onions

Why I Still Use Onion Powder

The Caramelized Onion Butter Topping

Why I Used American Cheese

Hawaiian Rolls Versus Slider Buns

How To Make These Ahead

The Real Star Here Is The Caramelized Onion

What makes these different from the classic onion soup mix sliders is that we are getting a lot of our onion flavor from actual onions.

I used Vidalia onions because I happened to have a beautiful bag of them, but they also happen to be perfect for this.

Vidalia onions are naturally sweet, and that sweetness becomes even more pronounced when you slowly caramelize them in butter.

You aren’t looking for crispy fried onions here.

The onions should become very soft, golden brown, and almost jammy. When you put them on the sliders, they practically melt into the ham and cheese.

Regular yellow onions will work if you can’t find Vidalias, but if Vidalia onions are available, I would use them.

Don’t Rush The Caramelized Onions

This is the one part of the recipe where you need a little patience.

I cook the sliced onions in butter and a little oil over medium-low heat for approximately 30 to 40 minutes.

Stir them occasionally, but you don’t have to stand over the skillet stirring constantly.

If the bottom of the skillet starts getting too dry or the onions are browning faster than they are softening, add a tablespoon or two of water.

That water will also help loosen all of those browned onion bits from the bottom of the pan.

Toward the end of cooking, I add Worcestershire sauce, onion powder, garlic powder, and black pepper.

You can also add a little sugar if you want to help the caramelization along, but Vidalia onions are already quite sweet, so this is optional.

When the onions are finished, reserve about two tablespoons before assembling the sliders.

Finely mince those reserved onions.

We are going to put them into the butter mixture for the tops of the buns, and this is one of my favorite parts of the whole recipe.

Let the rest of the onions cool for about 10 minutes before assembling your sliders.

Putting steaming-hot onions directly onto soft bread can create extra moisture, and nobody asked for a soggy-bottomed slider.

Why I Still Use Onion Powder

You may be wondering why I am using onion powder in a recipe that already contains two whole onions.

They do two different things.

The caramelized onions give you sweetness, texture, and that rich cooked-onion flavor.

The onion powder gives you a more concentrated savory onion flavor.

Remember, the inspiration for these was the classic ham and cheese slider made with powdered onion soup mix.

I didn’t want to completely lose that familiar flavor just because I was replacing the packet with fresh onions.

Using both gives you the best of both worlds.

The Caramelized Onion Butter Topping

This is what really ties the whole thing together.

I melt butter and add those finely minced reserved caramelized onions along with Worcestershire sauce, Dijon mustard, onion powder, garlic powder, dried parsley, celery salt, black pepper, and optional poppy seeds.

Then the whole mixture gets spooned over the tops of the slider buns.

Try to distribute the little caramelized onion pieces across all of the buns, and don’t worry if some of that seasoned butter runs down into the spaces between the sliders.

That’s exactly what you want.

As everything bakes, the onion pieces almost bake onto the tops of the buns while that seasoned butter works its way down into the sandwiches.

About The Poppy Seeds In My Pictures

Putting this here because I already know someone is going to look at the pictures and think I burned the tops of these sliders.

I did not.

I added poppy seeds to my butter mixture, and some of them clumped together a little bit when I spooned everything over the buns.

Those clusters got very dark as they baked, which makes a few spots on the tops of my buns look burnt in the pictures.

The buns themselves were perfectly golden and delicious.

The poppy seeds are completely optional. I happen to like them on these types of baked sliders, but you can leave them out if you want.

Why I Used American Cheese

Swiss cheese is probably what most people immediately think of when they think about ham and cheese sliders.

And Swiss would absolutely work here.

But I used American cheese, and I loved it.

American cheese gets incredibly creamy when it melts, and I thought that texture was perfect with the thinly shaved ham and soft caramelized onions.

I like to use cheese both underneath and on top of the filling.

Start with a layer of American cheese on the bottom buns, add the shaved ham, spread the caramelized onions over the ham, and then finish with another layer of cheese.

Besides giving you more melty cheese, that bottom layer also creates a little barrier between the bread and the filling.

Get The Ham Shaved Very Thin

I used ham off the bone and asked for it to be very thinly shaved.

I really recommend doing this if you’re getting your ham from the deli.

Rather than biting through one thick slab of ham, you get all of these delicate little folds and layers throughout the sandwich.

It also makes the sliders much easier to bite into.

You need approximately 3/4 to 1 pound of ham for 12 sliders, depending on how generously you want to fill them.

Hawaiian Rolls Versus Slider Buns

I know Hawaiian rolls are practically synonymous with baked ham and cheese sliders.

And I love them.

This time, though, I used a slightly larger traditional slider bun.

They are still soft, but they aren’t quite as sweet as Hawaiian rolls, and there is a little more bread to hold up to the filling.

I thought they were perfect here.

You can see exactly what I used in the video below.

If you prefer Hawaiian rolls, use them. You may want to start checking them a little earlier during the uncovered portion of baking because the sweeter tops can brown quickly.

Cover First, Then Uncover

Once the sliders are assembled and covered with the caramelized onion butter, cover the baking dish loosely with foil.

Bake them covered at 350°F for about 15 minutes.

This gives the center of the sandwiches time to get hot and the American cheese time to melt without over-browning the tops.

Then remove the foil and bake them for another 8 to 12 minutes.

This is when the tops get beautifully golden and that onion butter really bakes into the buns.

Let the sliders rest for about 5 minutes before cutting them apart.

Make The Caramelized Onions Ahead

If you are making these for a party, football game, or holiday, you can absolutely get the most time-consuming part out of the way ahead of time.

Make the caramelized onions a day or two in advance and store them covered in the refrigerator.

When you’re ready to make the sliders, take the onions out and let them lose some of their refrigerator chill before assembling.

I would personally wait to assemble the sandwiches and add the butter topping until closer to baking time.

You don’t want all of that butter and moisture sitting on the bread overnight.

What To Serve With Caramelized Onion Ham And Cheese Sliders

These can be a party appetizer, football food, or an easy dinner.

Because the sliders are rich, buttery, and cheesy, I particularly like serving something cool or crunchy alongside them.

Coleslaw would be perfect.

So would a cucumber salad, pickles, potato salad, or a cold pasta salad.

You could also serve these with soup and make a really easy soup-and-sandwich dinner.

If you are serving these for a party or game day, put out a couple of different salads and some chips and call it a day.

More Slider Recipes To Try

If you love a good slider as much as I do, I have plenty more where these came from. Sliders are one of my favorite things to make for parties, football games, holidays, or those nights when you want an easy dinner everyone can grab and eat. Here are a few more of my favorite slider recipes to try next. Just click each image for the recipe.

Frequently Asked Questions

Can I Use Regular Yellow Onions?

Yes. Regular yellow onions caramelize very well and will work perfectly in this recipe.

I used Vidalia onions because I had them and love their natural sweetness.

Can I Use Swiss Cheese Instead Of American?

Absolutely.

I tested and made these with American cheese because I wanted that really creamy melt, but Swiss cheese would be delicious with the ham and caramelized onions.

Can I Use Hawaiian Rolls?

Yes.

I used a slightly larger traditional slider bun this time, but Hawaiian rolls can be substituted.

Keep an eye on them toward the end of baking because their sweeter tops may brown a little faster.

Do I Have To Use Poppy Seeds?

No.

They are completely optional.

And if you do use them and they clump together like mine did, don’t panic when they get dark. Those dark little spots on my sliders are toasted poppy seeds, not burnt buns.

Why Is There Onion Powder If I’m Using Fresh Onions?

Because the two provide different flavors.

Fresh caramelized onions are sweet, rich, and soft.

Onion powder provides a concentrated savory onion flavor and helps give these some of the familiar flavor of the classic onion soup mix sliders.

Can I Make The Caramelized Onions Ahead?

Yes.

Make them a day or two ahead and refrigerate them in an airtight container.

Can I Assemble The Sliders The Night Before?

You technically can assemble the sandwiches ahead, but I prefer not to add the butter topping until shortly before baking.

For the best bread texture, my preference would be to make the onions ahead and assemble the sliders the day you’re serving them.

How Do I Keep The Bottoms From Getting Soggy?

Let the caramelized onions cool before putting them onto the bread.

I also put American cheese directly against the bottom bun before adding the ham and onions. That creates a little barrier between the bread and the more moist ingredients.

Can I Leave Out The Dijon Mustard?

You can, but there is only one teaspoon in the entire butter topping.

The sliders don’t taste strongly of mustard. It adds a little tang and helps balance all of the butter, cheese, ham, and sweet onions.