1 can red kidney beans
1 can pinto beans
1 can Navy beans
1 can pork 'n' beans
1 lg. onion, diced
1/3 c. mustard
2/3 c. ketchup
1 1/2 c. brown sugar
4 slices bacon, fried and crumbled
1 tsp. butter

Saute onion in butter for 2 minutes, medium heat. Add all other ingredients. Mix well. Pour into baking dish. Bake at 350 degrees for 45 minutes.