Mushroom Onion Swiss Burger
Mushroom Onion Swiss Burgers are tender beef burgers flavored with thyme and Dijon mustard and topped with sauteed mushrooms, caramelized onions, and plenty of nutty Swiss and Gruyere cheese.
Servings: 6 servings
Calories: 642kcal
Equipment
- cast iron skillet optional
- burger rings optional
- mushroom brush optional
- burger press optional
- cooking twine optional
- box grater optional for grating the Gruyere cheese
Ingredients
For the onion and mushroom topping:
- 2 tablespoon olive oil
- 2 large sweet onions sliced
- 4 fresh thyme sprigs tied together with cooking twine
- 1 teaspoon kosher salt use ½ teaspoon if using iodized salt
- ¼ teaspoon black pepper
- 2 pints cremini mushrooms cleaned and cut into slices
- 1 tablespoon mushroom base
- 2 tablespoons heavy cream
- 1 teaspoon apple cider vinegar
For the beef burgers:
- 2 pounds ground beef
- 1 tablespoon Dijon mustard
- 1 tablespoon mushroom base
- 1 teaspoon kosher salt use ½ teaspoon if using iodized salt
- ½ teaspoon black pepper
- 6 slices Swiss cheese
- 4 ounces shredded Gruyere cheese
- 6 brioche hamburger buns or your favorite variety of buns
Instructions
To make the onion and mushroom topping:
- Add olive oil to a large skillet over medium-high heat. Add the onions, salt, pepper, and fresh thyme to the skillet and cook, stirring occasionally, until the onions start to turn golden brown and caramelized. This will take approximately 7-8 minutes.
- When the onions have caramelized, reduce the heat to medium and add the sliced mushrooms to the skillet along with the mushroom base. Stir to combine and cook for 4-5 minutes.
- Add the cream and vinegar into the skillet and cook, stirring occasionally, for 2-3 additional minutes. Remove the onions and mushrooms to a bowl and keep warm. Remove the thyme sprigs before using. *Note - If making in advance, allow to cool and keep in a airtight container in the refrigerator for up to 4 days.
To make the beefy burgers:
- In a large bowl, combine the ground beef, mushroom base, Dijon mustard, salt and pepper until just combined, making sure not to overwork the beef.
- Place the burger mold on a sheet of parchment paper and gently press enough of the beef mixture into the mold to fill. Lift and shake the burger from the mold and return the formed burger to the parchment paper. Continue the same process with the remaining ground beef mixture.
- Heat the same skillet onion and mushroom skillet over medium-high heat. Once hot, add three burgers at a time to the skillet and press with a burger press or spatula to properly sear the outside of each burger. Cook for 4-5 minutes and flip the burgers to cook on the second side, using an instant read thermometer to test for doneness.
- Add the Swiss cheese slices and shredded Gruyere to the top of each cooked burger; cover to allow the cheese to melt. Once melted, remove the cooked burgers to a baking sheet fitted with a rack and keep the burgers warm in a low oven while preparing the remaining burgers in the same fashion.
- When all the burgers are cooked and keeping warm in the oven, toast the buns in the hot skillet (cut side down) for 60-90 seconds (or until toasted to your preference).
- Top each toasted bottom bun with a melted cheese burger and top each burger with a mound of caramelized onion and mushrooms before adding the toasted top bun to the burger. Serve hot and enjoy!
Notes
Store any leftovers, wrapped well, in the refrigerator for up to 5 days.
Burger patties may be frozen after cooking. Completely cool and partially freeze the burgers separately, and then wrap each burger in wax paper and store them in an airtight freezer container or freezer bag for up to 4 months.
Nutrition
Serving: 1serving | Calories: 642kcal | Carbohydrates: 38g | Protein: 50g | Fat: 33g | Saturated Fat: 15g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 12g | Trans Fat: 1g | Cholesterol: 141mg | Sodium: 1301mg | Potassium: 1420mg | Fiber: 3g | Sugar: 12g | Vitamin A: 430IU | Vitamin C: 7mg | Calcium: 482mg | Iron: 6mg
