Mushroom and Horseradish Cheeseburgers
Serves 4- 1/2 cup mayonnaise
- 1/4 cup prepared horseradish
- 1 3/4 teaspoons table salt, divided
- 2 tablespoons plus 1 teaspoon vegetable oil, divided
- 10 ounces cremini mushrooms, trimmed and sliced thin
- 1/2 onion, sliced thin
- 2 garlic cloves, minced
- 1 1/2 pounds 85 percent lean ground beef
- 2 teaspoons coarsely ground pepper
- 4 slices deli Swiss cheese (4 ounces)
- 4 brioche buns, toasted and buttered
Divide beef into four equal portions and gently form into 3/4-inch-thick patties. Sprinkle patties with pepper and remaining 1 1/4 teaspoons salt, pressing to adhere.
Heat remaining 1 teaspoon oil in the now-empty skillet over medium-high heat until just smoking. Transfer patties to skillet and cook until well browned on both sides, about 3 minutes per side. Divide mushroom mixture and Swiss cheese over patties, then cover and remove from heat. Let sit until cheese is melted, about 2 minutes.
Transfer burgers to a plate, tent with foil, and let rest for 5 minutes. Spread mayonnaise mixture on cut sides of buns. Transfer burgers to bun bottoms and cap with bun tops. Serve.




