2 pounds lean ground beef
1/2 cup diced onion
1 cup bread crumbs
1 cup milk
2 teaspoons salt
1/4 teaspoon pepper
1 cup (4 ounces) Wisconsin colby cheese, cut into 1/2 inch cubes
2 tablespoons butter
1 can (10 1/2 ounces) cream of mushroom soup
1 can (5 1/3 ounces) evaporated milk
1 can (4 ounces) mushrooms, drained
Combine ground beef, onion, breadcrumbs, milk, salt and pepper in a large mixing bowl. Shape meat mixture into about 15 large balls, pressing a cheese cube into center of each ball. In a heavy skillet, brown all sides in butter. Remove from pan and absorb excess grease on paper towel.
In a buttered casserole dish, combine cream of mushroom soup, evaporated milk and mushrooms; mix well. Add meatballs, coating each with gravy. Cover and bake for 30 to 40 minutes at 300° F.