Southern Barbecue Sauce

Melt the butter in a large, heavy saucepan over medium heat. Add
onions and garlic and stir while cooking until soft. Add water, chili
sauce, ketchup, vinegar, crushed red pepper, brown sugar,
mustard, salt and black pepper. Stir well.
Add lemon juice and two of the juiced halves to the saucepan.
Bring the sauce to a simmer and cook uncovered until the sauce
thickens and is reduced to about 3 cups, 1 hour or longer.
Remove from the heat and throw out the lemon halves. Cool and
refrigerate. The barbecue sauce can be stored for a week. Use it
to baste chicken, pork or beef.