San Antonio Barbecue Sauce

Ingredients

• 1 cup onions, finely chopped
• 1 garlic clove, finely chopped
• 2 tablespoons chili powder
• 1 cup apple cider vinegar
• 1/4 cup Worcestershire sauce
• 1/3 cup brown sugar
• 2 tablespoons prepared mustard
• 1 tablespoon celery seed
• 2 teaspoons cumin seeds, crushed
• 2 tablespoons butter
• 1/4 cup vegetable oil
• 2 cups ketchup
• 1/2 cup lemon juice