Slow-Cooked Barbacoa with Guajillo Chile Paste

Preheat a heavy skillet over medium heat. Place dried guajillo chiles into the skillet and cook, stirring occasionally, until they change color and expand, approximately 5 minutes. Remove the chiles from the skillet for a brief moment to cool down.

Meanwhile, toast cumin and cloves in the hot skillet until they start popping; take them out of the pan and set aside. Remove the stems, seeds, and veins from the chiles, and place them in a small bowl. Pour boiling water over the top of the chiles, cover it, and let them soak for 1 hour.

Grind the toasted cumin and cloves into a fine powder, then add it to a blender. Mix in ancho chile powder, onion, garlic, oregano, thyme, vinegar, and lime juice. Remove the chiles from their soaking water, add them to the blender along with 1/3 cup of the liquid, cover it, and blend until a smooth paste forms.

Place beef roast in a large mixing bowl, pour the guajillo chile paste over it, and coat the beef evenly with the paste. Cover the bowl with plastic wrap and refrigerate overnight.

Preheat your oven to 325 degrees F (165 degrees C). Transfer the beef and marinade to a roasting pan, arrange bay leaves on top, cover it tightly with aluminum foil. Bake in the preheated oven until the beef is extremely tender and can be easily pulled apart with a fork, approximately 6 hours. Let it stand at room temperature for 1 hour before discarding the bay leaves and shredding with two forks.