Dr. Pepper BBQ Sauce

INGREDIENTS
     4 tablespoons unsalted butter
     1 large yellow onion, chopped
     4 cloves garlic, chopped
     1 cup ketchup
     3 tablespoons tomato paste
     1 12-ounce can Dr. Pepper
     1/2 cup cider vinegar
     1/3 cup Worcestershire sauce
     1/2 cup packed dark brown sugar
     2 teaspoons ancho or New Mexican chili powder
     1 teaspoon fine-ground white pepper
     1 teaspoon kosher salt

INSTRUCTIONS

1. In a heavy saucepan, melt the butter.

2. Saute the onion and garlic in the butter until translucent, about 10 minutes.

3. Add all the remaining ingredients and simmer for about 15 minutes, until the flavors have blended. Continue cooking until the sauce begins to thicken, 20 to 30 minutes.

4. Taste and adjust the seasonings with salt and pepper if desired.

5. Let the sauce cool for about 10 minutes or until it is warm but no longer hot.

6. Puree with an immersion or traditional blender—this will make the sauce thicker.

7. Let finishing cooling. Keep the sauce tightly covered in the refrigerator for up to 2 weeks.