In a large, heavy saucepan, heat 5 to 6 inches of oil to 375 degrees F. Fry the tortillas, 1 by 1, in the hot oil until they are soft, about 10 seconds and drain on paper towels. Reserve, covered, in a warm spot. Heat wire "potato nest" baskets in the hot oil for several seconds, or until they are very hot. Fit a soft tortilla into the bottom basket and place the smaller basket on top of the tortilla. Immerse the baskets in the hot oil and cook until the tortilla is crispy and golden brown. Remove the tortilla cup from the basket and invert on paper towels to drain. Repeat the procedure with the other tortillas. (If you don't have a potato nest basket, you can also lay the tortillas 1 by 1 on the surface of the hot oil, then immediately push the center to the bottom with a small, empty tin can, thus creating a free form cup. Be sure to use tongs and heat resistant gloves to protect yourself.)
Cut the shrimp into piece the same size as the bay scallops. Refrigerate the shrimp, ahi, and scallops separately.
In a bowl, mix together the olive oil, lime juice, cilantro, red onion, and tomato and add salt and pepper, to taste. Add the seafood to this mixture and marinate, in the refrigerator, for 15 minutes to 45 minutes.
Place the tortilla cups on plates. Divide the ceviche among the cups and garnish with sprigs of cilantro.
Recipe courtesy of Wolfgang Puck, "The Wolfgang Puck Cookbook", Random House, 1986