Ingredients
- 1 teaspoon butter
- 1 cup finely chopped red onion
- 3 pounds ground beef
- 1 cup chopped mushrooms
- 1/2 cup ketchup
- 4 egg yolks
- 1/4 cup Worcestershire sauce
- 2 tablespoons horseradish mustard
- 4 teaspoons ground black pepper
- 1 tablespoon sea salt
Directions
Heat butter in a skillet over medium heat and cook and stir red onion until soft and translucent, about 5 minutes. Mix ground beef, cooked onion, mushrooms, ketchup, egg yolks, Worcestershire sauce, horseradish mustard, black pepper, and sea salt in a large bowl until thoroughly combined.
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BRANDED KITCHENWARE
Form the mixture into six 3/4-inch thick patties and cook in a large skillet over medium heat until burgers are juicy and browned, 5 to 7 minutes per side. An instant-read meat thermometer inserted into the center of a patty should read at least 160 degrees F (70 degrees C).