Barbecue Sauce Recipe

1 onion (diced)
1 tablespoon butter
1 cup ketchup
1 cup tomato sauce
2 tablespoons red wine vinegar
1 tablespoon Worcestershire sauce
1 teaspoon salt
1 teaspoon red pepper
1 teaspoon chili powder
2 tablespoons brown sugar
1/2 teaspoon celery salt
1 teaspoon black pepper
1 teaspoon dry mustard
1 tablespoon liquid smoke

Sauté onion in butter. Combine all of the ingredients except the liquid smoke. Simmer 15 minutes, then add liquid smoke.