Classic Ceviche

Ingredients

• 1 pound fresh, skinless snapper, bass, halibut, or other ocean fish fillets, cut into 1/2-inch dice
• 1 1/2 cups fresh lime juice
• 1 medium white onion, chopped into 1/2-inch pieces
• 2 medium-large tomatoes (about 1 pound), chopped into 1/2-inch pieces
• Fresh hot green chiles (2 to 3 serranos or 1 to 2 jalapenos), stemmed, seeded and finely chopped
• 1/3 cup chopped cilantro, plus a few leaves for garnish
• 1/3 cup chopped pitted green olives (manzanillos for a typical Mexican flavor)
• 1 to 2 tablespoons extra-virgin olive oil (optional)
• Salt
• 3 tablespoons fresh orange juice or 1/2 teaspoon sugar
• 1 large or 2 small ripe avocados, peeled, pitted and diced
• Tostadas, tortilla chips or saltine crackers, for serving