Follow these simple steps to prepare delicious fresh and tangy ceviche tostadas:

1. Prepare the Fish: Rinse the fresh fish fillets under cold water and pat dry. Cut the fish into small cubes.
2. Marinate the Fish: In a non-reactive bowl, combine the fish cubes and lime juice. Ensure the fish is fully submerged in the juice. Cover and refrigerate for 10-15 minutes, or until the fish turns opaque.
3. Add Vegetables: Once the fish is marinated, add the diced red onion, jalapeño peppers, diced tomatoes, diced cucumber, and chopped cilantro to the bowl. Gently mix everything together.
4. Season: Sprinkle salt and pepper to taste, adjusting to your preference. Stir well to incorporate the seasonings.
5. Assemble Tostadas: Take a tostada and spoon the ceviche mixture onto it, ensuring an even distribution of fish and veggies.
6. Garnish: Top with avocado slices if desired, and serve with lime wedges on the side for added zest.
7. Repeat: Continue assembling the remaining tostadas until all the ceviche is used.
8. Serve Immediately: Enjoy your fresh and tangy ceviche tostadas while they’re crisp!

These steps will guide you in crafting a sensational dish that embodies fresh and flavorful zest.