Homemade BBQ Sauce

Megan and I are having BBQ ribs tonight. I just used a standard BBQ rub on the meat, but I really wanted to make my own sauce for the glaze at the end. She's out grocery shopping now, so I haven't started the grill yet, but I did just make the sauce. It's very spicy and tangy. There's also a freshness to it that's missing from store-bought brands. The recipe is actually influenced by three cookbooks: The Joy of Cooking, the Weber book that came with my grill and another BBQ cookbook.

1/2 finely chopped medium onion
2 tablespoons of butter

On medium heat, heat butter until it bubbles. Add onions and sweat them until they are soft. Then add:

1/3 cup of ketchup
1 tablespoon of brown mustard
2 tablespoons of balsalmic vinegar
2 tablespoons of orange juice
1 tablespoon of worchester sauce
1 tablespoon of soy sauce (I prefer Maggi)
1 tablespoon of brown sugar
1/2 teaspoon of cayenne pepper
1/2 teaspoon of cumin

Stir on low heat until desired consistency.

Brush this sauce on whatever meat you are grilling for the last 15 min. Like I said, it's a little spicy and tangy. Several books recommend freshly grated ginger, but alas, I don't have any.