Tuna Tostadas with Chipotle Mayo, Avocado and Crispy Leeks (Contramar Style)

Servings: 6  tostadas, serving 6 as a light snack or an appetizer
I’m writing this recipe to include both crisp-frying the leeks and using the same oil to fry tostadas. You can step around all that by simply buying the Thai-style crispy shallots you find at Asian groceries (or even French’s crispy onions—not elegant, but tasty) and, of course, buying tostadas already fried, preferably from a local company to ensure freshness. Or, if you’d like to go the other way, making this even more spectacular, fry the leeks and tostadas and make your own mayonnaise, using lime juice instead of vinegar. (Or buy the lime juice-flavored mayo at a Mexican grocery.)

INGREDIENTS

  • 6 thin store-bought corn tortillas, preferably 4 to 5 inches in diameter (ones that are stale—at least not moist—are best)
  • 1 leek (white part only), roots cut off, cleaned, cut into rings about 1/8 inch thick
  • Oil for frying to a depth of 1 inch
  • Salt
  • 8 to 10 ounces sashimi-quality tuna, preferably a slab about 4 inches square and 2 inches thick (tuna belly is often the right thickness)
  • 2 tablespoons soy sauce
  • 2 tablespoons fresh orange juice
  • 1/4 cup best-quality mayonnaise (see note above)
  • About 1 tablespoon finely chopped canned chipotle chiles en adobo
  • 1 avocado, cut in half, pit removed, flesh scooped from skin and cut into 12 slices
  • 1 lime, cut into six wedges

INSTRUCTIONS

Fry the leeks and tostadas.  If the tortillas are at all moist, lay them out in a single layer to dry out.  Scoop the leeks into a bowl, cover with cold tap water and work them between your fingers to separate the rings.  Drain well and spread onto paper towels.  Thoroughly pat dry.  Heat the oil to 360 degrees.  In two batches, fry the leeks until they turn a rich golden and are beginning to crisp, about 3 minutes (they will not be completely crisp). Use a slotted spoon or skimmer spider to remove to a paper towel-lined baking sheet. When all are fried, spread out the leeks and sprinkle with salt.  One or 2 at a time, fry the tortillas until crisp, turning regularly, about 1 minute (the bubbling will have nearly stopped).  Drain on paper towels.  

Marinate the tuna. In flat dish (an 8x8-inch baking dish is perfect), mix together the soy and orange juice.  Slice the tuna into thin slices (about 1/8 inch) and lay into the pan in a shingled single layer, flipping each slice to season both sides with the marinade.  Let stand about 10 minutes.  

Make the chipotle mayonnaise.  In a small bowl, combine the mayonnaise and chopped chipotle.  

Assemble the tostadas.  Spread about a tablespoon on each tostada.  To finish each tostada, lift a couple slices of tuna from the marinade, lay them over the mayo, top with a generous sprinkling of the crispy leeks and a couple of avocado slices.  Serve with lime wedges.