Ultimate Smashed Burgers with Old Bay Fries and Caramelized Onion Special Sauce

These smashed burgers are all about texture-ultra-thin patties with lacy, crispy edges that give way to juicy, flavorful beef. Topped with gooey white cheddar, sweet caramelized onions and a homemade special sauce, they’re sandwiched between soft potato buns for the perfect bite.

On the side, crispy oven fries get a boost from Old Bay seasoning, making this a complete, crowd-pleasing meal. The special sauce doubles as a dip for the fries, so you get that tangy kick in every bite.

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Ingredients

12 ounce PotatoesView ingredient guideLike ingredientDislike ingredient

1 unit OnionView ingredient guideLike ingredientDislike ingredient

0.5 cup White Cheddar CheeseView ingredient guideLike ingredientDislike ingredient

20 ounce Ground BeefView ingredient guideLike ingredientDislike ingredient

1 tablespoon Old Bay SeasoningView ingredient guideLike ingredientDislike ingredient

1 unit KetchupView ingredient guideLike ingredientDislike ingredient

2 tablespoon MayonnaiseView ingredient guideLike ingredientDislike ingredient

2 unit Potato BunsView ingredient guideLike ingredientDislike ingredient

2 teaspoon Dijon MustardView ingredient guideLike ingredientDislike ingredient

1 teaspoon (tsp) SugarView ingredient guideLike ingredientDislike ingredient

4 teaspoon (tsp) Cooking OilView ingredient guideLike ingredientDislike ingredient

teaspoon (tsp) SaltView ingredient guideLike ingredientDislike ingredient

teaspoon (tsp) Black PepperView ingredient guideLike ingredientDislike ingredient

Instructions

1. Preheat oven to 425°F with a rack in the top position. Wash and dry potatoes; cut into ½-inch-thick wedges. Halve, peel and thinly slice the onion.
2. On a baking sheet, toss potato wedges with a drizzle of oil and half the Old Bay seasoning. Season lightly with salt and pepper (the seasoning already contains salt). Roast on the top rack until browned and crispy, 20-25 minutes.
3. While potatoes roast, heat a drizzle of oil in a medium nonstick pan over medium-high heat. Add sliced onion and cook, stirring occasionally, until browned and softened, 8-10 minutes. Stir in 1 teaspoon sugar and a splash of water; cook until onion is caramelized and jammy, 2-3 minutes more. Season with salt and pepper, then transfer to a small bowl.
4. In another small bowl, combine mayonnaise, ketchup, mustard and remaining Old Bay seasoning to taste. Set aside. Divide ground beef into 2 equal balls (4 balls for 4 servings) and season all over with salt and pepper.
5. Heat a drizzle of oil in the same pan over medium-high heat. Once hot, add the beef balls. Firmly flatten each ball with a spatula into very thin patties (watch for splatters). Cook until desired doneness, 3-4 minutes per side. During the last 1-2 minutes, top patties with cheddar and cover the pan to melt the cheese. Remove from heat.
6. Halve and toast the potato buns. Divide buns among plates and fill with patties, caramelized onion and half the special sauce. Serve with Old Bay fries and remaining special sauce for dipping.

Recipe Tips

FAQ

Can I use a different cheese?

Yes, you can substitute white cheddar with provolone, Monterey Jack or American cheese for a different flavor.

How do I prevent the patties from sticking?

Use a well-seasoned or nonstick pan and ensure it’s hot before adding the beef. A thin layer of oil also helps.

Can I make the fries ahead of time?

For best crispiness, serve fries immediately. However, you can reheat them in a 400°F oven for a few minutes to refresh.