Smash Burgers with Grilled Onions

Close view of smash burger with two beef patties, grilled onions, cheddar cheese, lettuce, and a side of fries.

Crispy-edged Smash Burger patties cooked on the griddle and stacked with cheddar, grilled onions, and zesty burger sauce—this Smash Burger Recipe is a next-level summer favorite.

Course Main Dishes

Cuisine American

Prep Time 15

Cook Time 20

Total Time 35

Servings

Calories 1301kcal

Author Michelle Ordever

Ingredients

For the Smash Burgers

2 pounds ground beef 80/20
2 tablespoon burger seasoning
Salt and pepper to taste
8 slices cheddar cheese
1 onion sliced thick
2 tomatoes sliced thick
½ leaf lettuce trimmed
4 hamburger buns

For the Burger Sauce

1 cup mayonnaise
½ cup ketchup
¼ cup spicy mustard
2 teaspoon onion powder
¼ teaspoon minced garlic
⅛ teaspoon white vinegar
1 tablespoon Frank's RedHot Sauce

US Customary - Metric

Instructions

Make the burger sauce:

Add all sauce ingredients to a blender.
Blend on medium-high until smooth and combined.
Transfer to a container and refrigerate for at least 2 hours.

Prepare the burger patties:

In a large bowl, combine the ground beef, burger seasoning, salt, and pepper. Mix with your hands until just combined.
Cover and refrigerate for 1–2 hours.
Remove from fridge. Using a large ice cream scoop, portion the beef into 8 balls.

Cook the burgers and onions:

Preheat your flat top grill to medium heat.
Add sliced onions and cook until lightly golden on each side. Set aside.
Place burger balls on the grill. Smash each down with a large spatula until about ¼ inch thick.
Season patties with burger seasoning, salt, and pepper.
Cook 5 minutes, then flip and smash again if needed. Cook to medium temperature.
Add a slice of cheddar to each patty. Cover and cook 1–2 minutes until melted.

Assemble the burgers:

Toast burger buns if desired.
Spread burger sauce on the top and bottom buns.
Place lettuce on the bottom bun. Top with two burger patties, grilled onion, and a slice of tomato.
Finish with the top bun. Serve and enjoy!

Notes

This Smash Burger Recipe is best cooked fresh and served hot for the crispiest edges.
The burger sauce can be made ahead and stored in the fridge for up to 3 days.
Top your Smash Burgers with extras like pickles, crispy bacon, or jalapeños.
Best enjoyed fresh, but leftovers can be stored in the fridge for up to 2 days.
Cooked patties can be frozen; wrap them well and freeze for up to 2 months. To thaw frozen patties, defrost overnight in the fridge. Reheat on a hot griddle or pan until heated through and edges crisp up again.

Nutrition