Tostada with Smoked Tuna Ceviche

Ingredients

• 6 ounces Acme Sesame Crusted Smoked Ahi Tuna, chopped
• 2 tablespoons white onion, minced
• 2 tablespoons red onion, minced
• 2 tablespoons English cucumber, diced small
• 2 tablespoons mango, chopped
• 2 tablespoons pineapple, chopped
• 1 tablespoon fresh cilantro, finely chopped
• 1 small Fresno chili, thinly sliced (seeds removed for less heat)
• 1 small serrano chili, thinly sliced (seeds removed for less heat)
• 1 teaspoon lemon zest
• Sea salt, to taste
• 4 crispy corn tostadas
• 1 large ripe avocado
• Juice of ½ a lime
• Salt, to taste