Ingredients
1 pound lean ground beef (90% lean)3 Italian turkey sausage links (4 ounces each), casings removed2 teaspoons Worcestershire sauce1/2 teaspoon garlic powder2 tablespoons balsamic vinegar1 tablespoon olive oil6 large portobello mushrooms, stems removed1 large onion, cut into 1/2-inch slices6 tablespoons crumbled feta or blue cheese6 whole wheat hamburger buns or sourdough rolls, split10 fresh basil leaves, thinly sliced
Preparation
Combine first 4 ingredients; mix lightly but thoroughly. Shape into six 1/2-in.-thick patties. Mix vinegar and oil; brush over mushrooms.
Place burgers, mushrooms and onion on an oiled grill rack over medium heat. Grill covered until a thermometer inserted in burgers reads 160° and mushrooms and onion are tender, 4-6 minutes per side.
Fill mushroom caps with cheese; grill, covered, until cheese is melted, 1-2 minutes. Grill buns, cut side down, until toasted, 30-60 seconds. Serve burgers on buns; top with mushrooms, basil and onion.
