1 tablespoon neutral oil
1 large egg
1 corn tortilla
1/4 cup leftover Refried Black Beans or canned (see note)
1/4 avocado, sliced
2 tablespoons Quick-Pickled Red Onions or Quick-Pickled Radishes and Carrots (see note)
1 tablespoon leftover Ancho-lada Sauce or store-bought (see note)
Pinch of Alfaalfa sprouts (optional)
Fresh cilantro leaves
Make the tostada: Heat a 10-inch nonstick skillet over medium-low. Once the pan is warm, add the oil. Crack the egg where the oil pools, using a silicone spatula to pull in the whites of the egg. If the whites of the egg begin to bubble, turn the heat down further or pull the pan off the heat for a second.
Cook for 1 minute, and then spoon the oil in the pan over the whites of the egg until cooked through. Carefully remove the egg from the pan. Set aside.
Add the corn tortilla to the leftover oil in the same pan. Turn the heat up to medium, and fry the tortilla for about 2 minutes on each side until toasted. In another corner of the pan, reheat the refried black beans until warm.
To serve, place the pan-fried tortilla on a plate, and top with a shmear of refried black beans. Garnish with avocado slices, the sunnyside egg, pickled vegetables, Ancho-lada sauce, alfalfa sprouts, if desired, cilantro, and cotija. Give it fresh squeeze of lime, and serve immediately.