Mix the ingredients for the marinade in a large bowl. Add the tilapia filets, coat well and marinate for 20 minutes.
Meanwhile, place your shredded cabbage in a colander and add the salt. Massage the cabbage with the salt a few times and set aside for 20 minutes. After 20 minutes, taste the cabbage, which will now be softer, sweeter and seasoned. If it is too salty for your taste, give it a quick rinse. Otherwise, it’s ready to use.
Make the white sauce by mixing all the ingredients together. Thin it out slightly with a couple drops of water. Set aside.
Heat a large pan. Take the filets out of the marinade and sear them on one side for about 2-3 minutes, or until the sides of the fish turn opaque. Flip for 2 more minutes or until the fish is fully cooked through and can be flaked easily with a fork into big chunks.
Assemble your tostada by placing a few chunks of fish on top, followed by some cabbage and yogurt sauce. Drizzle with some hot sauce and garnish with fresh cilantro. Enjoy as is or with any additional garnish you like, such as sliced avocado, chopped tomatoes or another squeeze of lime. To eat, break with a fork and enjoy as glamorous nachos!