1/4 teaspoon black pepper
In medium-sized saucepan over medium heat, warm oil. Add onions, chiles and garlic; cook, stirring frequently, about four to five minutes, until onion and chiles are tender but not browned.
Stir in beer; mix well until foam dissolves. Add chili sauce, molasses, mustard, tomato paste, lemon juice, Worcestershire sauce, cumin, salt and pepper. Whisk well to combine all ingredients. Bring mixture to a boil; reduce heat to low and simmer 10 minutes, stirring several times, until thick.
Let sauce cool completely. Pour into clean jar with tight-fitting lid. Use immediately, or store sauce in refrigerator for up to three weeks.
Nutrition information per 1/4-cup serving: 110 calories, 3 grams fat; 0 grams saturated fat; 0 grams trans fat and 18 grams carbohydrate.