Basic BBQ Sauces

4 large onions, chopped
3 tablespoons vegetable oil for sautéing
1-28 ounce can tomato puree
3-28 ounce cans tomatoes with juice
2-1/2 cups white vinegar
4 tablespoons packed dark brown sugar
4 tablespoons granulated sugar
2 tablespoons salt
2 tablespoons freshly cracked black pepper
2 tablespoons paprika
2 tablespoons chili powder
4 tablespoons molasses
1 cup orange juice
2 tablespoons Liquid Smoke
8 tablespoons brown (Dijon-style) mustard

In a large, heavy-bottomed saucepan, sauté the onion in the oil over medium-high-heat until golden brown, about 7 to 10 minutes. Add all the remaining ingredients, bring to a boil, then reduce the heat and simmer uncovered at the lowest possible heat for 4 hours. (This long cooking removes as much acidity as possible from the tomatoes.)
Puree sauce in 2, 3, or more batches to prevent it from spilling out of your food processor or blender.

Variations:
Mexican
1 teaspoon ground cumin
1 teaspoon chili powder
4 tablespoons lime juice (about 2 limes)
10 cilantro sprigs
Asian
2 teaspoons minced ginger
8 tablespoons soy sauce
4 tablespoons rice wine vinegar
2 tablespoons sugar
1 tablespoon sesame oil
Makes about 1 Gallon