Ingredients:
1 1/2 tablespoons vegetable oil
1 large onion, roughly chopped
4 cloves garlic, smashed, peels removed
1 1/2 teaspoons dry mustard
1 1/2 teaspoons chili powder
1 1/2 teaspoons onion powder
1 24-ounce bottle ketchup (3 cups)
1 cup cider vinegar
1/4 cup Worcestershire sauce
3/4 cup dark brown sugar
1/4 cup honey (optional)

Instructions:

Heat oil in a large pot. Add onions and garlic, sweat until softened, about 5 minutes. Add mustard, chili powder and onion powder, and cook, stirring until fragrant. Add ketchup, vinegar, Worcestershire sauce, brown sugar, and honey (if desired). Stir to combine and cook on low heat until thickened and reduced by half, about 1 hour.

Puree sauce in a blender until completely smooth. Process according to USDA approved canning methods and store, or keep refrigerated in a sealed container in the refrigerator for up to 1 week. 

Recipe from Allison Fishman.