If you spend much time in Texas, you will no doubt note that there is a great BBQ shack every quarter mile or so along the wonderful intra-state Texas highways. Of the many sauces around the state, this one is from the Hill Country of central Texas where beef and lamb are kings of the slow-smoking barbecue pit. Influenced by the hearty German pioneers of the area, this is a sweet, very savory tomato-based sauce. It adds a wonderful complexity to barbecued beef brisket and beef ribs and even lamb shanks. The sauce keeps well covered and refrigerated for at least a week.
In medium saucepan over medium heat, melt the butter. Add the garlic and stir until it is fragrant, about 30 seconds. Stir in the ketchup, brown sugar, Worcestershire sauce, lemon juice chipotles, cayenne, salt, pepper and liquid smoke (if using). Bring the pot to a boil, then reduce the heat to medium-low. Simmer the sauce, stirring occasionally, until it has reduced to about the recipe amount and thickened slightly, about 15 to 30 minutes.