4 oz. (1 c.) shredded cheddar cheese
2.5 oz. jar sliced mushrooms (drained)
6 slices bacon (crisply cooked, crumbled)
1/4 c. mayonnaise

Combine all ingredients and mix well. Grill burgers, or cook in broiler and place topping on burgers when they are almost done. Continue cooking until cheese is melted. 6 to 8 servings.