– Place lime juice, vinegar, habanero pepper, chopped mango, ginger, salt, and pepper in the blender. Process until you have a very smooth sauce. Place this sauce in a bowl and add the shrimp to marinate. (The shrimp will cook with the lime and vinegar acidity)
– While the shrimp is marinating, prepare the tostadas. Mix masa-harina with the lard and warm water until you form a smooth dough. If it needs more water, add a few teaspoons at a time.
– Cook over a hot griddle, turning twice. Let them dry on the griddle until they are crispy. Remove and place on the serving plates. (You can also use regular store-bought tortillas and toast them on the griddle.)