Mushroom Swiss Burger Onions (Print Version)
A juicy beef patty topped with sautéed mushrooms, Swiss cheese, and caramelized onions.
# What You'll Need:
→ Burgers
01 - 1.5 lbs ground beef (80/20 blend)
02 - 1 tsp kosher salt
03 - 0.5 tsp freshly ground black pepper
04 - 1 tbsp Worcestershire sauce
→ Caramelized Onions
05 - 2 large yellow onions, thinly sliced
06 - 1 tbsp unsalted butter
07 - 1 tbsp olive oil
08 - 0.5 tsp salt
09 - 1 tsp sugar (optional)
→ Sautéed Mushrooms
10 - 8 oz cremini or button mushrooms, sliced
11 - 1 tbsp unsalted butter
12 - 1 tbsp olive oil
13 - 1 clove garlic, minced
14 - 0.25 tsp salt
15 - 0.25 tsp black pepper
16 - 1 tsp fresh thyme leaves (optional)
→ Assembly
17 - 4 slices Swiss cheese
18 - 4 brioche or hamburger buns, split and toasted
19 - 4 tbsp mayonnaise or aioli (optional)
20 - Lettuce leaves (optional)
# How-To Steps:
01 - Melt butter and olive oil in a large skillet over medium heat. Add sliced onions, salt, and sugar if using. Cook, stirring occasionally, for 15-20 minutes until deep golden and caramelized. Adjust heat to avoid burning. Remove from heat and set aside.
02 - In a separate skillet over medium-high heat, melt butter and olive oil. Add sliced mushrooms and cook 4-5 minutes until browned. Stir in garlic, salt, pepper, and thyme if using; cook 1-2 additional minutes. Remove from heat.
03 - Combine ground beef, salt, black pepper, and Worcestershire sauce in a mixing bowl. Form into four equal patties slightly larger than the buns.
04 - Preheat grill or skillet to medium-high. Cook patties 3-4 minutes per side for medium doneness. In the final minute, place a slice of Swiss cheese atop each patty, cover to melt thoroughly.
05 - Lightly toast the split buns on the grill or in a toaster until golden.
06 - Spread mayonnaise or aioli on the bottom bun if desired. Add lettuce leaves, place the burger patty, then top with sautéed mushrooms and caramelized onions. Cover with the top bun.
07 - Serve immediately accompanied by preferred side dishes.
# Expert Tips:
01 -
- The onions cook down so sweet and jammy they taste like something you'd order at a steakhouse, not make on a weeknight.
- Every component can be prepped ahead, so when it's time to eat, you're just assembling magic instead of scrambling.
02 -
- Onions need time—if you rush them on high heat, they'll char instead of caramelize, and you'll lose all that sweetness.
- Let the burgers rest for a minute after cooking so the juices redistribute instead of running all over your plate the second you cut in.
03 -
- Use a cast iron skillet for the burgers if you're cooking indoors; the heat retention gives you a better crust than nonstick ever will.
- If your buns are on the soft side, toast them a little longer or lightly butter them first to create a barrier against moisture.