adapted from Gourmet magazine (June issue)
Take 2-3 lbs brisket and roast at 250 for appx 8 hrs in enough beer to cover, fat side up. I like to spike the beer with garlic and onion, and rub the top of the exposed brisket with my current dry rub of choice (which right now happens to come from Goode Company BBQ). Remove and shred. Add back reduced beer as needed for moisture and flavor (you probably won’t want to throw out any of the beefy goodness, to be honest).
Toss 3/4 lb tomatoes with vegetable oil and broil until soft and charred. While broiling, toast 3 dried chiles (guajillo), stemmed and seeded, over medium heat in a dry skillet until pliable and slightly changed in color, about 30 seconds. Transfer chiles to a bowl of hot water and soak for 20-30 minutes, until soft.
Over the same skillet, toast 1/3 t peppercorns, 1/4 t cumin seeds, 3 whole allspice, and 1 clove until fragrant, about 1 min. Blend all spices, soaked chiles, tomatoes, 1/2 c chopped white onion, 3 cloves garlic, and chiles de arbol to taste (1-3) until smooth. Add beef beer, if any is left, or chile water, if necessary, for moisture, up to 2 cups. Add salt to taste.
Heat 2 T oil in a pan, add sauce and simmer until slightly thickened (about 5 minutes). Mix in beef until heated through, or serve sauce on side with tortillas, lime wedges, avocados, sliced onions, and sour cream.