1 1/4 lb 93% lean ground beef
8 oz crimini mushrooms, minced
1 small onion, minced
1 1/2 tablespoons soy sauce
1 tablespoon Worcestershire sauce
6 slices fontina cheese
6 brioche buns
2 tablespoons grainy Dijon
2 tablespoons mayonnaise
freshly ground black pepper
In a medium bowl, combine the ground beef, mushrooms, onion, soy sauce and Worcestershire sauce until well mixed. Form into 6 patties.
Prepare grill according to manufacturer’s instructions. Grill the burgers for 5-8 minutes on each side or until desired doneness. When in the last minute or so of grilling, top with cheese and allow to melt. Remove to a platter.
In a small bowl, whisk together the Dijon, mayonnaise, and pepper. Spread on rolls. Top with burgers. Serve immediately.
Mushrooms are one of my favorite toppings for burgers. I shy away from them when making burgers at home because it usually involves me stuck inside sauteeing mushrooms and onions while the burgers cook on the grill outside in the sunshine. That’s no fun! So for these hamburgers, I mixed in super finely chopped mushrooms and onions into the burger. All of the flavor and less work! Plus the mushrooms (chopped to the point of almost ground beef texture) stretched 1 1/4 lbs of ground beef into 6 good-sized burgers while adding a deeply savory note. I upped the umami factor by adding soy sauce and Worcestershire which made the burgers moist and flavorful without. Adding the mock mustard aioli, fontina and brioche just added to the wow factor. If you like savory, rich (but not heavy!) burgers, this one is for you!