BBQ Polish Sausage

1 medium onion -- chopped
1 tablespoon butter
1 cup catsup
1/4 cup brown sugar
1 tablespoon vinegar
1 teaspoon chili powder
1 tablespoon prepared mustard
1 Kielbasa -- sliced

Saute onion in butter, until tender.

Add rest of ingredients except meat, bring to boil.

Reduce heat and cover and simmer for 30 minutes or so.

Pour into greased casserole, stir in meat.

Cover and bake at 350ºF for 15 minutes or until hot.