For the chicken and assembly: Heat a large pan over high heat. Cook the chicken breasts until golden, then pour over 1/2 cup of the dressing and continue to cook, while tearing the chicken apart into smaller pieces. Once the chicken is fully cooked, add the pineapple slices to the pan. Bring the heat to a low simmer and let the chicken and pineapple cook in the dressing for another 5 minutes.
Meanwhile, steam or grill the tortillas until slightly warm and pliable, 10 to 30 seconds.
Divide the lettuce, tomatoes and onions between the tortillas, and then top evenly with the chicken and pineapples. Pour the remaining dressing on top. Tightly fold the wrap up, starting with the sides. Once rolled and whole, slice the wrap in half at an angle and present on a plate. You can garnish your wraps with parsley, tomato, pineapple slices, and/or more dressing.