DO-AHEAD TIP: Cook chicken.
COOKING INSTRUCTIONS: Heat the olive oil in a skillet over medium heat; add garlic, oregano, basil, salt and pepper and cook for 15 seconds.
Stir in next 5 ingredients (onion through tomato); sauté until veggies are tender, 7 to 10 minutes. Add cubed chicken and cook for 5 minutes or until heated through.
Fill lettuce leaves with chicken mixture and top with cheese... enjoy!