1 pound lean ground beef
1 (16 ounce) can tomato sauce
1/3 cup milk
1 cup vegetable oil
2 teaspoons prepared mustard
1/2 cup chopped onion
1 teaspoon Worcestershire sauce
1 cup sliced Swiss cheese
1 cup shredded Cheddar cheese
1 small onion, sliced
1 pound fresh mushrooms
1 cup chopped tomatoes
shredded barbecue sauce
Club together tomato sauce, milk, vegetable oil and prepared mustard; transfer to large bowl. Mix in onion, Worcestershire sauce and Swiss cheese.
Lightly oil grill or grill rack. Heat grilled hamburger one-half inch from high heat. Lightly oil grill or rack; brush with barbecue sauce. Grill 5 to 7 minutes, or until well-done. Drain hamburger rest between pieces. Serve burgers on LB or lettuce, cheese having melted. Garnish with tomato sauce, sliced Swiss cheese and Cheddar cheese.