50 to 60 dried chiles de árbol
1 1/2 tablespoons sesame seeds
2 tablespoons shelled pumpkin seeds
1/4 teaspoon cumin seeds or 1/4 teaspoon ground
1/8 teaspoon ground allspice
2 cloves
1 teaspoon dried Mexican oregano
1 scant teaspoon salt
2 cloves garlic, peeled and roughly chopped
3/4 cup cider vinegar

Stem the chiles, then roll them between your thumb and fingers, pressing gently to loosen the seeds inside. Break in half, shake out as many seeds as possible, then place in a blender jar.

Heat an ungreased skillet over medium-low heat. Stir the sesame seeds for several minutes until they brown and pop; scoop into the blender jar. Add pumpkin seeds to the skillet. When the first one pops, stir constantly for several minutes until all are golden and have popped up into a round shape.

Pulverize the cumin, allspice and cloves in a mortar or spice grinder, then add to the blender jar along with the oregano, salt, garlic and vinegar. Blend for several minutes until the mixture is orange-red and feels smooth when a drop is rubbed between your fingers. Strain through a sieve, working the solids back and forth and pressing them firmly. Stir in 3/4 cup water, then pour into a bottle, cover and let stand for 24 hours before serving.