The Best Barbecue Sauce
2 tablespoons vegetable oil
1 medium onion, chopped (about 1 cup)    
2 cloves garlic, smashed
3 cups ketchup
1/2 cup apple cider vinegar
1/4 cup packed dark brown sugar
1/4 cup steak sauce
1/4 cup Worcestershire sauce
3 tablespoons molasses
3 tablespoons yellow mustard
1/2 teaspoon ground celery seed
Kosher salt
1 to 2 teaspoons liquid smoke, optional
Instructions:
Heat the vegetable oil in a medium pot over medium heat. Add the onions and garlic and cook, until the onions are golden, 6 to 7 minutes. Stir in the ketchup, 1 cup water, the vinegar, brown sugar, steak sauce, Worcestershire sauce, molasses, mustard, celery seed and 1 teaspoon salt. Bring to a boil, then reduce the heat to medium-low and simmer until the onions are tender, about 15 minutes. Stir in the liquid smoke, if using. Strain the sauce, pressing on the solids to extract any liquid.
