Put a medium sized pan on the stove and set to medium heat.
Spray the pan with the olive oil spray and cook the chicken for 6-7 minutes on each side until the internal temperature is 165 degrees Fahrenheit, or until chicken is cooked through.
While the chicken is cooking, in a large salad bowl, combine romaine lettuce, cherry tomatoes, cucumber, red onion, and Kalamata olives.
Top with grilled chicken breast slices and crumbled feta cheese.
Drizzle with tzatziki sauce and olive oil.
Toss gently to combine all ingredients.
