In a large 12-inch nonstick skillet, heat the oil over medium heat and add the onion and carrots. Add the garlic, salt and pepper and cook for 2-3 minutes, until the vegetables start to soften.
Season the chicken pieces lightly with salt and pepper and add to the skillet with the onions and carrots. Cook, stirring often, until the chicken pieces are cooked through, 4-5 minutes.
Stir in the soy sauce and maple syrup and cook over medium heat for 2-3 minutes, letting the soy sauce and maple syrup bubble and simmer.
Stir in the cashews, cooking until they are just heated through. Season to taste with additional salt and pepper, if needed.
Serve in lettuce leaves topped with tomatoes and cucumbers (the freshness adds a delicious element to the flavors!).
