Place a large nonstick skillet over medium-high heat. Add sesame seeds and cook until lightly toasted, shaking pan frequently, about 2 to 3 minutes; transfer seeds to a shallow dish and set aside.
Whisk water, soy sauce, maple syrup, sherry, ginger and five-spice powder together in a small bowl; set aside.
Combine flour, salt and pepper together in a shallow dish; add chicken and turn to coat. Shake chicken pieces to remove excess flour.
Heat oil in a large nonstick skillet over medium-high heat. Add chicken and sauté until browned on all sides, about 5 minutes. Add soy sauce mixture to chicken and cook until sauce thickens and is almost evaporated, about 2 to 3 minutes more.
Dip chicken pieces in toasted sesame seeds and serve, drizzled with any additional soy sauce mixture. Yields about 4 strips per serving.