Oven BBQ Spareribs

Recipe courtesy of cclovesdw

6-8 pieces country style spare ribs
2 tablespoons butter
1 large onion, sliced
1 cup water
2 tablespoons brown sugar
2 tablespoons vinegar
1 cup ketchup
1 tablespoon dry mustard

Brown butter and onion, until the onion is tender.  Add all other
ingredients (except ribs), bring to a boil. Reduce heat and simmer 15
minutes.  Pour over ribs in roaster and cover.  Bake at 350 for 2
hours.