Mushroom Swiss Burger Onions (Print Version)
Savory beef patty layered with sautéed mushrooms, Swiss cheese, and caramelized onions for a rich flavor.
# What You Need:
→ Burgers
01 - 1 lb ground beef (80/20 blend)
02 - 1 tsp kosher salt
03 - ½ tsp freshly ground black pepper
04 - 1 tsp Worcestershire sauce
→ Caramelized Onions
05 - 2 large yellow onions, thinly sliced
06 - 1½ tbsp unsalted butter
07 - 1 tbsp olive oil
08 - ½ tsp salt
09 - ½ tsp sugar
→ Mushrooms
10 - 8 oz cremini or button mushrooms, sliced
11 - 1 tbsp unsalted butter
12 - 1 clove garlic, minced
13 - ¼ tsp salt
14 - ¼ tsp black pepper
15 - 1 tsp fresh thyme leaves (optional)
→ Assembly
16 - 4 slices Swiss cheese
17 - 4 brioche or hamburger buns, split
18 - 2 tbsp mayonnaise (optional)
19 - Lettuce leaves (optional)
# Preparation Steps:
01 - In a large skillet over medium heat, melt butter with olive oil. Add sliced onions, salt, and sugar. Stir frequently and cook for 20–25 minutes until onions turn deeply golden and caramelized. Transfer to a bowl and set aside.
02 - In the same skillet, melt butter over medium heat. Add mushrooms and cook for 6–8 minutes until moisture evaporates and they begin to brown. Add garlic, salt, pepper, and thyme if desired; sauté for another 1–2 minutes. Remove from heat.
03 - Combine ground beef, Worcestershire sauce, salt, and pepper gently in a bowl. Divide into 4 equal portions and shape into patties with a slight indent in the center of each.
04 - Preheat grill or skillet over medium-high heat. Cook patties for 3–4 minutes per side for medium doneness. During the last minute, place a slice of Swiss cheese on each patty and cover until melted.
05 - Lightly toast the split buns on the grill or in a toaster until golden and crisp.
06 - Optionally spread mayonnaise on bottom buns, add lettuce leaves if desired, then top with cheeseburger patties, sautéed mushrooms, caramelized onions, and cover with top buns. Serve immediately.
# Expert Advice:
01 -
- The sweet, jammy onions balance the savory beef in a way that feels almost like cooking magic.
- Mushrooms soak up butter and garlic, making this feel fancier than it actually is to pull together.
- Swiss cheese melts into every crevice, and the whole thing comes together in under an hour.
02 -
- The caramelized onions are worth the wait—rushing them means you'll just get soft brown onions instead of that sweet, concentrated flavor that makes the whole burger sing.
- Don't press the burgers while they cook; it squeezes out all the juices and leaves you with a sad, dry patty.
03 -
- Make your patties the night before and keep them in the fridge—they hold together better and cook more evenly when cold.
- The caramelized onions keep in the fridge for days, so batch-make them on a weekend and you have gourmet burgers ready whenever the craving hits.