From Gabriela Camara of Contramar restaurant
1 tablespoon lemon juice
1 large egg
1/4 rounded teaspoon salt
1/2 cup light olive oil
1. Put lemon juice, egg and salt in a blender. Slowly start blending the ingredients, adding oil little by little, until the mayonnaise is thick and you have added all the oil.
2. Add the chipotle chile and blend in. Makes three-fourths cup. You will have some left after making the tostadas.
1 1/2 cups oil (for deep frying)
8 (3-inch-diameter) corn tortillas
2 leeks (about 1 cup sliced)
2 teaspoons olive oil
10 ounces sashimi-quality tuna, sliced one-fourth inch thick then cut in half, if necessary
1/4 cup soy sauce
1/4 cup lemon juice
1 Hass avocado, peeled, pitted and cut into eighths
1/4 cup chipotle mayonnaise
1. Heat the oil in a deep skillet to 350 degrees. Fry each tortilla until crisp, about 2 minutes. Drain between paper towels. Set aside.
2. Slice the leeks (white part only) into one-fourth-inch-wide julienne. Heat the olive oil in a skillet over very low heat. Add the leeks, sprinkle with a little salt and cook until soft but not browned, about 5 to 7 minutes.
3. Marinate the tuna slices in the soy sauce and lemon juice for 2 minutes. Drain.
4. Spread 1 1/2 teaspoons chipotle mayonnaise on each tostada. Divide the tuna among the tostadas. Top the tuna with the leeks and add a slice of avocado to each tostada.