This mushroom Swiss burger brings diner-style comfort straight to your kitchen. Juicy beef patties are topped with deeply caramelized onions, buttery sautéed mushrooms, and perfectly melted Swiss cheese, all layered on toasted brioche buns. It’s a timeless burger that delivers rich flavor with simple, familiar ingredients.
Why You’ll Love This Recipe
This recipe focuses on technique rather than complexity, giving you big flavor without unnecessary steps. The slow-cooked onions add natural sweetness, the mushrooms bring savory depth, and the Swiss cheese melts beautifully over the patties. Everything comes together quickly once the toppings are ready, making it ideal for both casual weeknight dinners and relaxed weekend meals.
Ingredients
(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)
1 ½ tablespoons unsalted butter, plus extra for toasting the buns
2 large yellow onions, vertically sliced
1 teaspoon salt, divided
1 ½ pounds lean ground beef
1 tablespoon olive oil
8 ounces cremini mushrooms, sliced
4 thick slices Swiss cheese
4 brioche buns
Mayonnaise, to taste
Butter lettuce, as needed
Directions
Melt the butter in a large cast-iron skillet over medium-high heat. Once melted, add the sliced onions and stir to coat them evenly. Cook for 8 to 10 minutes, stirring occasionally, until the onions soften.
Reduce the heat to medium, add ¼ teaspoon of the salt, and continue cooking the onions for 30 to 50 minutes, stirring occasionally, until they are deeply golden and caramelized. If the pan begins to brown too quickly, add a small splash of water to loosen the browned bits.
While the onions cook, divide the ground beef into four equal portions and gently form them into patties. Slice the mushrooms if not already prepared.
When the onions are done, transfer them to a plate and set aside. Increase the heat to medium and add the olive oil to the same skillet. Add the mushrooms and cook for about 10 minutes, stirring occasionally, until soft and lightly browned. Season with ¼ teaspoon of salt and black pepper to taste, then remove from the pan.
Increase the heat to medium-high and add the burger patties to the skillet. Season with the remaining ½ teaspoon of salt. Cook for 3 to 4 minutes until a crust forms, then flip and cook for another 3 to 4 minutes, or until the burgers reach an internal temperature of 165°F. Place a slice of Swiss cheese on each patty during the last 2 minutes of cooking to melt.
Remove the burgers from the pan. Wipe out the skillet, lightly butter the brioche buns, and toast them cut-side down until golden.
To assemble, spread mayonnaise on the buns, add butter lettuce, top with a cheeseburger patty, followed by caramelized onions and mushrooms. Serve immediately.
For extra richness, add a spoonful of garlic butter to the mushrooms while they cook.
Swap brioche buns for whole wheat or potato buns for a different texture.
Use a blend of mushrooms such as cremini and portobello for deeper flavor.
Add a mild mustard or garlic aioli to the buns for a sharper contrast.
Storage/Reheating
Store leftover burger patties, onions, and mushrooms separately in airtight containers in the refrigerator for up to 3 days. Reheat the patties and toppings gently in a skillet over medium heat until warmed through. Toast fresh buns before assembling for best texture.
FAQs
Can I make the caramelized onions ahead of time?
Yes, caramelized onions can be made up to 4 days in advance and stored in the refrigerator.
What type of ground beef works best?
Lean ground beef works well, but a slightly higher fat content can make the burgers even juicier.
Can I cook these burgers on a grill?
Yes, cook the patties on a preheated grill and prepare the onions and mushrooms in a skillet separately.
How do I keep the burgers from drying out?
Avoid pressing down on the patties while cooking and remove them as soon as they reach the correct temperature.
Can I use a different cheese?
Yes, mild cheeses that melt well work best, but Swiss provides the classic flavor.
Are these burgers freezer-friendly?
The cooked patties can be frozen, but the onions and mushrooms are best enjoyed fresh.
What’s the best way to slice onions for caramelizing?
Slice them vertically with the grain to help them hold their shape during long cooking.
Can I add sauce besides mayonnaise?
Yes, a simple garlic sauce or mild burger sauce pairs well with the flavors.
Do I need a cast-iron skillet?
Cast iron is ideal, but any heavy-bottomed skillet will work.
What sides go well with this burger?
Crispy fries, roasted potatoes, or a simple green salad complement it nicely.
Conclusion
This mushroom Swiss burger proves that classic combinations never go out of style. With juicy beef, sweet caramelized onions, savory mushrooms, and melty cheese, it delivers comfort and flavor in every bite. Once you master this recipe, it’s sure to become a regular favorite at your table.
A juicy and flavorful mushroom Swiss burger topped with caramelized onions, sautéed mushrooms, and melted Swiss cheese, served on toasted brioche buns.
Ingredients
1 ½ tablespoons unsalted butter, plus extra for toasting the buns
2 large yellow onions, vertically sliced
1 teaspoon salt, divided
1 ½ pounds lean ground beef
1 tablespoon olive oil
8 ounces cremini mushrooms, sliced
4 thick slices Swiss cheese
4 brioche buns
Mayonnaise, to taste
Butter lettuce, as needed
Instructions
Melt butter in a large skillet over medium-high heat. Add onions and cook for 8–10 minutes until softened.
Reduce heat to medium, add ¼ teaspoon salt, and cook onions for 30–50 minutes until deeply golden and caramelized, stirring occasionally.
While onions cook, divide ground beef into 4 patties. Slice mushrooms if needed.
Transfer onions to a plate. In the same skillet, heat olive oil over medium. Add mushrooms and cook for about 10 minutes until browned. Season with ¼ teaspoon salt and pepper, then remove from pan.
Increase heat to medium-high and cook burger patties, seasoning with remaining salt. Cook 3–4 minutes per side or until internal temp reaches 165°F. Add Swiss cheese during the last 2 minutes of cooking.
Remove patties. Wipe skillet, butter buns, and toast cut-side down until golden.
Assemble burgers: spread mayonnaise on buns, add lettuce, burger patty, caramelized onions, and mushrooms. Serve immediately.
Notes
Make caramelized onions in advance to save time.
Try garlic butter or aioli for extra flavor.
Use different mushrooms or cheeses to change the flavor profile.
Don’t press down on burgers while cooking to retain juiciness.
