In the summer, I like to focus on great bacon and heirloom tomatoes to create a tostada with the spirit of a BLT. Grilling tortillas to crispiness gives them a rustic char I like. Avocado mayo, with a good amount of cilantro, adds a touch of Oaxaca.
Lay the tortillas out in a single layer on a baking sheet. Cover with a dish towel or napkin and let dry until they are leathery, about 30 minutes (depending on their moistness). This will enable them to crisp thoroughly on the grill.
Meanwhile, in a food processor or blender, combine the egg yolks and lime juice and pulse until blended. With the machine running, slowly drizzle in the oil (the yolks and oil should emulsify and become creamy). Add avocado, green chile and cilantro; process to mix well. Taste and season with salt, usually about 1 teaspoon. Scrape the mayonnaise into a bowl and set aside.
When the tortillas are ready, turn on a gas grill to medium or light a charcoal fire and let the coals burn until medium hot and covered with gray ash.
When you’re about ready to serve, lay several tortillas on the grill and turn every 20 seconds or so until they’re golden-brown all over and cracker-crisp—this will take 5 to 10 minutes, depending on the heat of your fire. Brush the top of each tortilla generously with the bacon fat or oil and let the tortillas crisp a little longer, then remove them to a serving platter.
Spread on some spicy avocado mayo and top with a portion of the tomatoes. Sprinkle each tostada with about a tablespoon of bacon, garnish with cilantro leaves and immediately serve to your guests while you make the next round.