2 tablespoons butter
1 medium onion, chopped
1/2 cup water
1/2 cup prepared chili sauce (I use Heinz the most. Maggi is good if you can get that brand)
1/2 cup ketchup
1/4 cup cider vinegar
2 tablespoons lemon juice
2 tablespoons brown sugar
2 tablespoons Worcestershire sauce
1 tablespoon molasses
2 teaspoons salt
2 teaspoons dry mustard
1/2 teaspoon black pepper
1/2 teaspoon paprika

Method-

Melt butter in a skillet over medium low heat; add chopped onion. Cover and cook until translucent, about 10 minutes, stirring occasionally. Blend in the remaining ingredients. Bring sauce to a boil. Reduce heat and simmer, uncovered, for 30 minutes, stirring occasionally. Serve at room temperature