Sprinkle the tilapia with 1/2 teaspoon salt and 1/4 teaspoon black pepper. Heat the oil in a large skillet over high heat until hot. Add the fish and cook, turning once, until golden and cooked through, about 10 minutes. Let the fish cool to warm, then shred with a fork.
Put the shredded fish and the oil from the skillet in a large bowl and toss with the cilantro, onion, lime juice, Worcestershire, jalapeño, 1 teaspoon salt and 1/2 teaspoon black pepper. Chill until ready to use.
Toast the tortillas directly over a burner set on medium, turning, until blackened in spots. Stack the tortillas as toasted.
Serve the tilapia salpicon with the tortillas, lettuce, sour cream and lime wedges.