French Onion Smash Burgers
This is a full-on burger night kind of dinner. Crispy-edged beef, gooey Gruyère, sweet caramelized onions, tangy burger sauce, and a few pickles if you want them all piled onto a toasted bun. It’s rich, messy, deeply satisfying, and exactly what you want when dinner needs to feel like a treat.
Servings: FOUR
INGREDIENTS
1 pound 85/15 ground beef
2 medium yellow onions, thinly sliced
1 tablespoon olive oil
1 tablespoon unsalted butter
1 teaspoon Worcestershire sauce
4 ounces Gruyère cheese, thinly sliced (8 slices) or grated
4 gluten-free hamburger buns
12 dill pickle slices, optional
Burger Sauce
1/3 cup mayonnaise
2 tablespoons ketchup
1 tablespoon Dijon mustard
1 teaspoon Worcestershire sauce
1 teaspoon pickle brine
PREPARATION
Caramelize onions: Heat olive oil and butter in a large cast iron or stainless steel skillet over medium-low heat. Add onions, season with salt and pepper, and cook for 25 to 30 minutes, stirring occasionally, until deeply golden, soft, and jammy. Stir in 1 teaspoon Worcestershire sauce and cook for 1 minute. Transfer to a bowl.
Make burger sauce: Stir mayonnaise, ketchup, Dijon, 1 teaspoon Worcestershire sauce, and pickle brine together in a small bowl.
Form beef: Divide beef into 8 loose 2-ounce balls, handling as little as possible.
Toast buns: Wipe out skillet if needed and toast buns cut-side down over medium heat until golden. Set aside.
Smash burgers: Heat skillet over high heat until very hot. Working in batches if needed, add beef balls with plenty of space between them. Immediately smash each ball very thin with a sturdy metal spatula. Season with salt and pepper and cook, undisturbed, for about 2 minutes until deeply browned with crisp edges.
Flip and melt cheese: Scrape underneath each patty firmly to preserve browned crust, flip, and cook for about 1 minute. Divide Gruyère among 8 patties. Top each with a second patty and cook just until cheese melts and beef is cooked through.
Plate: Spread burger sauce over buns. Add double smash patties, caramelized onions, and optional dill pickles. Close burgers and serve hot.
Notes:
For the best crust, use a heavy cast iron or stainless steel skillet and let it get very hot before adding the beef.
Smash each beef ball immediately after it hits the skillet. Once the crust begins to form, don’t press the patties again or you’ll squeeze out juices.
