In a large skillet over medium heat, combine the onion, garlic, and whiskey. Simmer for 10 minutes, or until onion is translucent. Mix in the ground black pepper, salt, ketchup, tomato paste, vinegar, liquid smoke, Worcestershire sauce, brown sugar, and hot pepper sauce.
Bring to a boil. Reduce heat to medium-low, and simmer for 20 minutes. Run sauce through a strainer if you prefer a smooth sauce.
1/2 onion, minced
4 cloves garlic, minced
3/4 cup bourbon whiskey
1/2 teaspoon ground black pepper
1/2 tablespoon salt
2 cups ketchup
1/4 cup tomato paste
1/3 cup cider vinegar
2 tablespoons liquid smoke flavoring
1/4 cup Worcestershire sauce
1/2 cup packed brown sugar
1/3 teaspoon hot pepper sauce, or to taste