Almost Heinz Barbecue Sauce

Ingredients

• 1 medium onion, chopped
• 1/4 cup butter
• 1 cup ketchup
• 1/2 cup beef stock
• 2 tablespoons Worcestershire sauce
• 2 tablespoons lemon juice
• 3 tablespoons red wine vinegar (can use cider vinegar)
• 1 teaspoon garlic powder
• 1/4 cup brown sugar (can use more)
• 1 1/2 teaspoons mustard powder
• 1 teaspoon season salt
• 1/2 teaspoon fresh ground black pepper (to taste)