Mushroom Swiss Burger Caramelized Onions (Printable)
Juicy beef patties with sautéed mushrooms, Swiss cheese, and sweet caramelized onions on toasted buns for a gourmet classic.
# What You'll 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 (optional)
→ 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 (optional)
→ Burger Patties
13 - 1.3 pounds ground beef (80% lean)
14 - 1/2 teaspoon salt
15 - 1/2 teaspoon black pepper
16 - 4 slices Swiss cheese
→ Burger Assembly
17 - 4 burger buns, split and toasted
18 - 2 tablespoons mayonnaise (optional)
19 - 1 tablespoon Dijon mustard (optional)
20 - Lettuce leaves (optional)
# How To Make:
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 (if using) 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), 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.
06 - Serve immediately with your favorite side.
# Expert Tips:
01 -
- The combination of sweet onions and earthy mushrooms creates layers of flavor that make every bite interesting
- Melting Swiss cheese over the hot patty brings everything together in the most satisfying way possible
02 -
- Caramelizing onions takes longer than you expect, but rushing them results in cooked onions, not caramelized ones
- Do not press down on the burgers while they cook or you will lose all those precious juices that keep them moist
03 -
- Start the onions first since they take the longest, and use that time to prep everything else
- Let the burgers rest for a couple of minutes after cooking so the juices redistribute