Serves 6

1 pound boneless red snapper, swordfish fillets, or other very fresh fish, cut into ½ inch cubes; shrimp or scallops can be substituted for some of the fish
1 ½ cups freshly squeezed lime juice (about 7 large limes)
2 medium ripe tomatoes, finely diced
3 pickled jalapeno or Serrano chiles, finely chopped
½ cup sliced green olives
3-4 tablespoons olive oil
2 teaspoons lime juice, if needed
about ¾ teaspoon sea salt
½ teaspoon coarsely ground black pepper
½ teaspoon dried oregano, preferably Mexican
1 firm but ripe avocado, peeled, pitted, and cut into ½ inch cubes

For the Garnish

6 Bibb lettuce leaves (optional)
3 tablespoons finely chopped cilantro
large crisp tortilla chips or store bought chips

Put the fish and other seafood in a nonmetallic bowl and cover with lime juice. Mix thoroughly, cover tightly with plastic wrap, and refrigerate for 4-5 hours, until the fish is no longer opaque. Drain off any excess lime juice. Ceviche can be refrigerated, after draining, for up to 12 hours, but it tends to become a little chewy after this much time.

About 1 hours before serving, stir in the tomatoes, onion, jalapenos, and olives, if using them. Add enough olive oil to lightly coat all the ingredients. Taste and, if needed, sprinkle on some additional lime juice. Add the salt, pepper, and oregano, and return to the refrigerator until just before serving. Taste again for seasoning and mix in the avocado. Spoon into a large attractive bowl or place on lettuce leaves on individual plates. Sprinkle with cilantro. Serve with the tortilla chips for scooping up the ceviche.

Note: If you worry about possible fish parasites, it is recommended that you use seafood that has been commercially frozen for two days, then thawed. The shrimp can be precooked.