In-N-Out Flying Dutchman Onion Burgers (Easy Cookout Recipe)

A Taste Of The West Coast Comes To The Midwest Barbecue

These In-N-Out Flying Dutchman Onion Burgers (Easy Cookout Recipe) take inspiration from one of the most popular items on In-N-Out’s secret menu. Featuring juicy cheeseburgers topped with thick, savory roasted onions. Perfect for summer cookouts, backyard parties, or an easy weeknight dinner, these burgers deliver all the flavors of the classic Flying Dutchman while making it easy to feed a crowd.

I came up with this recipe while thinking about ideas for our summer cookouts and the block party we’re hosting at our new house. While I’m definitely a fan of In-N-Out Burger whenever I’m in Southern California, I wouldn’t call myself their biggest fan. The burgers are good, but for me it’s all about ordering them Protein Style, wrapped in crisp lettuce instead of a bun, and adding those delicious grilled onions from the Flying Dutchman. That combination has always been my favorite part of the menu.

Since I knew I’d need a way to make a large quantity of onions for a crowd, I started experimenting. I did this by roasting thick onion slices on sheet pans instead of standing at the grill caramelizing onions for hours. The result was even better than I expected.

The onions become tender, deeply caramelized, and loaded with savory flavor from the beef tallow, butter, Worcestershire, and beef bouillon. If I were feeding a large crowd, I would make two big trays of these ahead of time. Keep them warm in a foil pan near the grill. You can quickly reheat them on the grill while the burgers cook. You can also pop them back into the oven to warm through before serving. They’re the perfect cookout topping. They make it easy for everyone to build their own burger just the way they like it.

In-N-Out Lore

In-N-Out Burger is a beloved California burger chain that was founded in 1948 by Harry and Esther Snyder in Baldwin Park, California. Known for its simple menu, fresh ingredients, and cult-like following, the restaurant has become famous for its made-to-order burgers, hand-cut fries, and not-so-secret “secret menu” items.

Items like Animal Style burgers, Protein Style burgers wrapped in lettuce, and the Flying Dutchman. While the menu remains intentionally simple, In-N-Out’s commitment to quality and consistency has made it one of the most recognizable and iconic burger chains in the United States.

Crisp Lettuce Is Key

If you serve these burgers on crisp iceberg lettuce instead of a bun, this is often referred to as “Protein Style” at In-N-Out Burger. I love serving them this way because the cold, crunchy lettuce provides the perfect contrast to the warm, juicy burger and rich roasted onions.

The iceberg lettuce adds a fresh bite that keeps the burgers from feeling too heavy and allows the flavors of the beef, cheese, and caramelized onions to really shine. Even people who aren’t watching their carbs often find themselves loving the crisp texture and lighter feel of a lettuce-wrapped burger.

Other Toppings Ideas

While I kept these burgers simple with lettuce, cheese, and the roasted onions, there are plenty of other toppings that would be delicious. Add sliced tomatoes, dill pickles, pickled jalapeños, crispy bacon, sautéed mushrooms, avocado, or even a fried egg for an extra indulgent burger. Thinly sliced red onion adds a nice crunch, while pepper jack cheese can give the burgers a little kick. You can also set up a burger bar at your cookout and let guests customize their burgers with all of their favorite toppings.

In-N-Out Burger Sauce

If you want to make it fully the In-N-Out inspiration, make a simple copycat burger sauce:

Combine 1/2 cup mayonnaise, 2 tablespoons ketchup, 2 tablespoons sweet pickle relish, 1 teaspoon yellow mustard, 1 teaspoon white vinegar, and a pinch of black pepper.

Stir until smooth and refrigerate for at least 30 minutes before serving. The sauce is creamy, tangy, slightly sweet, and tastes great spread on buns, drizzled over lettuce-wrapped burgers, or served as a dipping sauce for fries.

Topping The Onions For Baking

The secret to these onions is the mixture of butter, beef tallow, beef bouillon, and Worcestershire that coats them before roasting. The beef tallow helps recreate some of the rich flavor you get from onions cooked on a burger griddle, where they slowly soften and caramelize alongside beef patties.

I like combining the tallow with butte. The butter adds richness and helps the onions develop beautiful golden edges while the tallow brings that classic burger restaurant flavor.

I also used Worcestershire powder in this recipe. This is one of my favorite secret ingredients and something I use in countless recipes. If you’re curious where else I use it, search “Worcestershire powder” on my website and you’ll find plenty of inspiration. Don’t worry if you don’t have the powder on hand though, regular Worcestershire sauce works just as well. It will still give the onions that savory, slightly tangy flavor that makes them so irresistible.

The Real In-N-Out Fans Know This Info

One of the things that makes In-N-Out so popular is its famous “secret menu”. Many of these items are no longer much of a secret. They aren’t listed on the standard menu board and are ordered by name.though. The secret menu allows customers to customize their burgers and fries in dozens of ways . This has created combinations that have become almost as famous as the restaurant itself. If you’ve never been to In-N-Out before, learning the secret menu is practically part of the experience.

Popular In-N-Out Secret Menu Items

Protein Style – Any burger wrapped in crisp lettuce instead of a bun.

Animal Style Burger – A burger cooked with mustard on the patty and topped with extra spread, pickles, and grilled onions.

Animal Style Fries – French fries topped with melted cheese, grilled onions, and In-N-Out spread.

Flying Dutchman – Two beef patties with two slices of cheese and no bun. Some locations will also make the popular onion-wrapped version using whole grilled onion slices.

Grilled Cheese – All the toppings of a cheeseburger without the beef patty.

3×3 – Three beef patties and three slices of cheese.

4×4 – Four beef patties and four slices of cheese.

Extra Toasted Bun – A bun that is toasted longer for additional crunch and flavor.

Mustard Grilled Patty – A beef patty cooked with mustard directly on the grill before serving.

Well Done Fries – Fries cooked longer for a crispier texture.

Light Well Fries – Fries cooked slightly longer than normal but not as dark as well-done fries.

Extra Spread – Additional In-N-Out sauce on your burger or on the side for dipping.

Chopped Chilis – Pickled yellow chilis added to your burger for extra heat and flavor.

My personal favorite order is a Protein Style burger with grilled onions.This is what inspired this recipe in the first place. It gives you all the flavor of a classic burger while letting those delicious onions take center stage.