My daddy was the best out door bar-b-que cook I knew. When it came to chicken or ribs on the grill, he was the king. He often cooked out on a job site and invite the people he did business with to eat. This is his recipe I learned by his side to make. He was a cook in the army during WW11 and he learned how texas barbque was better than ours. Down here the vinegar based sauce is more commonly used but he made his with the ketchup base. I would have July 4th gatherings at my house and he would make the sauce. The last year I did this he came and said I needed to learn how. So glad I did.
In a large stock pot melt one stick of butter. Slice the onion thin and add to the hot butter. Slowly cook until tender with the garlic, salt,red pepper and black peper.
When oninons are tender add the mustard and stir till disolved. Add the vinegar,bottle of worcheshire,texas pete,apple cider vinegar and the brown sugar. Stir until well blended cover the pot and allow to cook about 5 minutes not burning
Final step: Add the ketchup and stir until blended well. Add water to the ketchup bottle about half way shake well to mix left over ketchup in it. Pour into the pot and stir and let cook about 5 more minutes.
It is important to know this sauce is best used over chicken cooked on charcoal. It just achieves its best flavor that way. Once the chicken is done daddy would submerge the chicken into the sauce and cook a liitle longer on each side not to burn just to set the flavor.
If you are grilling ribs and want to use this sauce add celery seed about a tablespoon to the recipe and I don't know why daddy said so and I do it.
prepare the grill with the charcoal and let embers have a little white ash top before place clean chicken over the coals. Grill about 30 min on skin side down first flip and grill 30 min on other side. If chicken is done submerege in the pot of barbque sauce and lay back on grill and let cook a few minutes on both sides to set in the char grilled sauce flavor. Watch carefully as not to let burn at this stage. We cover our grill all the way the cooking of the chickens. This is after they start cooking and coals will want to begin to flame up so then is when we close the open vented grill , you should know how to adjust the air flow if you are a out door griller.