In shallow glass dish, combine olive oil, cilantro, lime juice, lime rind, chili powder and cumin; add chicken, turning to coat. Sprinkle with salt and pepper. Cover and refrigerate for 1 to 3 hours.
Drain chicken, reserving marinade. Preheat grill to medium heat; grease grate well. Grill chicken for 5 minutes; turn and brush with marinade. Grill for 7 to 10 minutes or until chicken is tender and no longer pink inside. Wrap tortillas in foil and heat on grill or in oven during last 5 minutes of cooking time.
Thinly slice chicken. Divide chicken, lettuce, Cheddar, tomato, red pepper and onion among tortillas; roll up tortillas. Serve with salsa and guacamole (if using).
Filippo Berio’s classic, balanced Extra Virgin Olive Oil. Taken from the first cold pressing of the olives, this oil is ideal for sauces, marinades, drizzling and dipping.