This is called "Mutha Sauce", from the Dinosaur BBQ cookbook. It is a sweet and spicy sauce that is used in all their recipes. I modified it a little so it wouldn't have so many ingredients for me to buy.

1/8 cup vegetable oil
1/2 cup minced onion
1/4 cup minced green pepper
1 jalapeno pepper, seeded and minced
1 tbsp minced garlic
1 14oz can tomato sauce
1 cup ketchup
3/8 cup Worcestershire sauce
1/2 cup water
1/8 cup lemon juice
1/2 cup brown sugar
1/8 cup spicy brown mustard
1/2 tbsp chili powder
2 tsp cayenne pepper
3 tsp white wine vinegar
salt and pepper

Heat oil over medium high heat in saucepan. Saute garlic and jalapenos for a few minutes, then add onions and green peppers and cook until soft, seasoning with salt and pepper. Add all the other ingredients, bring to a boil, and simmer on low heat for 10 minutes.