Begin by draining and rinsing two cans of chickpeas thoroughly under cold water to remove excess sodium. In a large mixing bowl, use a fork to gently mash the chickpeas until they're roughly broken down yet still chunky, about 2–3 minutes.

Next, add diced red onion, chopped Roma tomatoes, diced cucumber, and shredded green leaf lettuce to the mashed chickpeas. Toss in minced serrano peppers and chopped cilantro. Gently toss the mixture together.

For the marinade, blend together lime juice, minced garlic, soy sauce, and any remaining cilantro and serrano peppers. Process until the mixture is smooth.

Pour the marinade over the chickpea mixture and add a sprinkle of ground nori powder if using. Stir everything together gently and refrigerate for at least 30 minutes.

To serve, spread a layer of vegan mayo onto crispy corn tostadas, spooning the marinated Chickpea Aguachile Verde on top, and garnish with avocado slices.