An excellent all-purpose barbecue sauce. Goes well with chicken or pork.
2 ounces unsalted butter (1/2 stick)
1/2 sweet onion, very finely chopped
1 1/4 cups ketchup
1/2 cup apple cider vinegar
1/4 cup Worcestershire sauce
2 tablespoons Dijon mustard
1/4 cup firmly packed brown sugar
juice of 1 lemon
1 tablespoon freshly ground black pepper
Heat the butter in a saucepan over medium heat. Add the onions and simmer until soft and melted, 5 to 7 minutes. Add ketchup, vinegar, Worcestership sauce, mustard, brown sugar, lemon juice, and pepper. Simmer until flavors smooth and mellow, about 10 minutes. Store in a covered container in the refrigerator.