2 lbs. lean ground beef
1 egg
3/4 tsp. salt
1 1/2 c. spaghetti sauce, divided
1/2 c. bread crumbs
2 tsp. instant minced onion
1 1/2 c. grated Mozzarella cheese
1 (4 oz.) can sliced mushrooms

Combine meat, egg, salt, 3/4 cup spaghetti sauce, bread crumbs, and onion; blend thoroughly. Pat mixture flat on waxed paper; top with cheese and mushrooms. Roll up and place in 12 x 8 x 2-inch loaf pan. Bake in 375 degree oven 30 minutes; drain. Top with remaining spaghetti sauce and bake additional 30-45 minutes.