2 to 3 hours
Don’t be afraid to eat your plate. It’s totally acceptable when you have a tostada, a deep-fried corn tortilla piled high with beans, meat, cheese, salsa and … the possibilities are limitless. It’s a delightful mess to eat (not first-date material unless you’re with someone really cool) and probably best done by breaking off shards of crispy tortilla (the “plate”) to scoop up the creamy beans and oh-so-tasty chorizo. You’ll be dancing in the streets.
See Cook’s Note on the variability and freshness of beans.
for the beans
In a medium saucepan, pour the boiling water over the beans — enough to cover them by an inch or so — and let stand for an hour. (Alternately, cover with cold water and soak for 6 hours.) Drain off that water and cover with the cold water. Add the pancetta, garlic, oregano, bay leaf, chile and onion. Cover and bring to a boil over high heat, skimming off any foam. Reduce the heat to maintain a simmer. Cover and cook, stirring occasionally, until very tender, 1 to 1½ hours.
for the tostada
Set a wire rack over a baking sheet and place rack within reach of your stove. Heat the oil in a small (8-inch) cast iron pan over medium heat until the oil is hot, about 8 minutes. Carefully slide one tortilla into the oil and cook, turning every 30 seconds until golden brown and crispy, 2½ to 3 minutes. Drain crispy tortilla on rack. Repeat frying remaining tortillas, one at a time. Let the oil cool completely before discarding or straining through a fine mesh sieve into a clean container to reuse another time.
for the chorizo
Shred the chorizo on the large holes of a box grater. Heat the oil in a 10-inch skillet, add the chorizo and cook until it renders a little of its fat, about 2 minutes. Add the onions and garlic and continue to cook until the onions are soft and the chorizo is just starting to brown, about 5 more minutes. Remove chorizo with a slotted spoon and place on a paper-towel-lined plate.
to refry the beans
Wipe out the skillet and heat the oil. Scoop the beans (leaving the pancetta, onion and bay leaf behind) with a slotted spoon into the skillet. Mash with a potato masher until about half the beans are smooth and half are mostly whole. Continue to fry until they dry out a little, about 5 minutes. Stir in the lime juice and season with salt and pepper.
Place crispy tortillas on a serving platter and spread ¼ cup of the bean mixture over each one. Sprinkle on 2 tablespoons of the chorizo, followed by 2 slices of avocado, 1/4 cup of shredded cabbage, 2 tablespoon pico de gallo, and 1 teaspoon of sour cream. Garnish each tostada with a tablespoon of cilantro leaves and evenly scatter the cheese over the tostadas. Serve with lime wedges.
Theories abound on how to properly cook dried beans. Here’s what we know: soaking can speed up the process, but it’s not entirely necessary, the beans will just take longer to cook. Older beans will take the longest. It’s nearly impossible to tell how old they are when you buy them, which is why cook times vary so much in recipes. A quick soak sort of bridges the gap. Add salt after they’ve cooked, as well as any acid, such as lime juice, for maximum absorption.