Mushroom Swiss Burger Caramelized Onions (Print Version)
Juicy beef burgers with Swiss cheese, mushrooms, and sweet caramelized onions on toasted buns
# What You Need:
→ Caramelized Onions
01 - 2 large yellow onions, thinly sliced
02 - 2 tablespoons unsalted butter
03 - 1 tablespoon olive oil
04 - 1/2 teaspoon salt
05 - 1 teaspoon balsamic vinegar
→ Sautéed Mushrooms
06 - 9 ounces cremini or button mushrooms, sliced
07 - 1 tablespoon unsalted butter
08 - 1 tablespoon olive oil
09 - 1 clove garlic, minced
10 - 1/4 teaspoon salt
11 - 1/4 teaspoon black pepper
12 - 1 teaspoon fresh thyme leaves
→ Burger Assembly
13 - 1.3 pounds ground beef (80% lean)
14 - 1/2 teaspoon salt
15 - 1/2 teaspoon black pepper
16 - 4 slices Swiss cheese
17 - 4 burger buns, split and toasted
18 - 2 tablespoons mayonnaise
19 - 1 tablespoon Dijon mustard
20 - Lettuce leaves
# How to Make It:
01 - In a large skillet over medium heat, melt butter with olive oil. Add sliced onions and salt. Cook, stirring occasionally, until onions are deeply golden and caramelized, about 18–20 minutes. Add balsamic vinegar in the last minute. Remove from skillet and set aside.
02 - In the same skillet, melt butter with olive oil over medium-high heat. Add mushrooms and cook, stirring occasionally, until browned and their moisture has evaporated, about 6–8 minutes. Stir in garlic, salt, pepper, and thyme. Sauté for another 1–2 minutes. Remove from heat.
03 - Divide ground beef into 4 equal portions and gently shape into patties slightly larger than your buns. Season both sides with salt and pepper.
04 - Heat a grill, grill pan, or skillet over medium-high heat. Cook patties for 3–4 minutes per side for medium doneness, or until desired doneness. In the last minute, place a slice of Swiss cheese on each patty, cover, and let melt.
05 - Spread mayonnaise and mustard on the cut sides of toasted buns if desired. Place lettuce on the bottom bun, add the burger patty with melted Swiss cheese, top with sautéed mushrooms and caramelized onions. Finish with the top bun.
# Expert Hints:
01 -
- The combination of sweet caramelized onions and earthy mushrooms creates layers of flavor that make every bite interesting
- These burgers taste like something you would order at a restaurant but are actually straightforward to make at home
02 -
- Rushing the caramelized onions is the biggest mistake you can make with this recipe
- Letting the mushrooms cook long enough to brown properly makes all the difference in their flavor
03 -
- Do not press down on the burgers while they cook or you will lose all those delicious juices
- Toast the buns until they are golden and slightly crispy to prevent them from getting soggy