Mince the onion and celery the finer the better. Simmer in vegetable oil until soft.

Mix the rest of the ingredients together, add once the veggies are soft and simmer on low for at least 30 minutes to reduce liquid and concentrate the flavor. You may simmer as long as you like to make the sauce thicker and get out the vinegar taste. If you put it on something while you are grilling it will get rid of the vinegar taste.