Whiskey BBQ Sauce

Ingredients

• 1 cup good-quality organic ketchup
• 1/2 cup tomato passata or puree
• 1/2 cup beef stock
• 3 shots bourbon whiskey
• 1/4 cup Worcestershire sauce
• 2 tablespoons light brown sugar
• 2 tablespoons cider vinegar
• 1 teaspoon coarse black pepper
• 1 teaspoon celery seed
• 1 tablespoon chili powder or hot paprika
• 1 rib celery, minced with leafy tops
• 1/4 cup grated onion
• 2 large cloves garlic, grated or finely chopped