Slice zucchini into ribbons with a vegetable peeler. Combine with sliced red onion, lemon zest, lemon juice, and olive oil. Season with salt and pepper and set aside to marinate for about 30 minutes.
Meanwhile, shred rotisserie chicken. (Alternatively, season 1 pound chicken cutlets with salt and pepper and broil until cooked through.)
Add shredded chicken to marinated zucchini along with chopped toasted almonds and fresh parsley.
Build four sandwiches with the chicken mixture (including juices) and romaine lettuce leaves, if using.
Recipe adapted from: www.marthastewart.com