Lightly-cooked cauliflower tossed with lime, kumquats, and red onion and served on a crispy corn tortilla. Vegan and gluten-free! Store-bought tostada shells (basically flat, crispy corn tortillas) can be found in the ethnic section of most grocery stores. But if you’d like to bake your own; heat oven to 350°F. Lay corn tortillas on a baking sheet and brush with a little oil on both sides. Sprinkle one side with salt and bake 10-15 minutes or until crispy, flipping tortillas halfway through.