- 6 dried guajillo chiles
- 1 dried ancho chile
- 4 rib pork chops (thin, 1/2- inch, bones, 1 lb total discarded)
- 1/2 teaspoon cumin seeds
- 1/4 teaspoon black peppercorns
- 1 whole clove
- 1 cinnamon stick
- 2 tablespoons cider vinegar
- 2 large garlic cloves (quartered)
- 1 teaspoon dried oregano
- 1 teaspoon salt
- 3 tablespoons vegetable oil
- 4 sesame seed hamburger buns (or Mexican cemita rolls)
- 2 avocados
- 1/2 cup leaves (fresh papalo, or cilantro leaves)
- 1 1/2 cups oaxaca cheese (or mozzarella cheese, shredded)
- 4 chipotle chiles in adobo (finely chopped)
- 1/2 white onion (large, thinly sliced)
- 1 plum tomato (large, thinly sliced crosswise)
- Discard chile stems and cut guajillo and ancho chiles open lengthwise. Discard seeds and ribs.
- Heat a dry heavy skillet over moderate heat until hot, then toast chiles, a few at a time, turning and pressing down with tongs, until softened and fragrant, about 10 seconds per side.
- Transfer chiles to a bowl, then cover with hot water and soak until softened, about 20 minutes.