Mushroom Swiss Burger Onions (Printable)
Juicy beef patty with Swiss cheese, sautéed mushrooms, and sweet caramelized onions on a toasted bun.
# 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)
→ Burgers
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 (optional)
19 - 1 tablespoon Dijon mustard (optional)
20 - Lettuce leaves (optional)
# Directions:
01 - Melt butter with olive oil in a large skillet over medium heat. Add sliced onions and salt. Cook, stirring occasionally, until onions are deeply golden and caramelized, about 18–20 minutes. Add balsamic vinegar if using during 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 is reached. In the last minute, place a slice of Swiss cheese on each patty, cover, and let melt.
05 - Spread mayonnaise and mustard on 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 and serve immediately.
# Expert Tips:
01 -
- The combination of sweet slow-cooked onions and earthy mushrooms transforms an ordinary burger into something that feels special enough for date night at home
- Everything except the patties can be prepared ahead, making weeknight dinner feel effortless even though it tastes like you spent all day cooking
02 -
- The onions need low and slow heat to develop proper caramelization, and if they start browning too quickly or sticking, reduce your temperature and add a splash of water
- Don't press down on your burgers while they cook because all those flavorful juices will escape, leaving you with dry patties
03 -
- Always slice mushrooms with a sharp knife rather than tearing them by hand, because clean cuts help them brown more evenly and look much more appetizing
- If your onions start drying out before they're properly caramelized, add a tablespoon of water and stir, which helps deglaze the pan and keeps everything cooking evenly