In a large bowl, combine the chicken, cornstarch, salt and pepper, toss to coat.
Heat the oil in a large skillet or wok over medium-high heat. Add the chicken, and cook 4-5 minutes or until the chicken is golden brown. Transfer chicken to a paper towel-lined plate.
Add butter to the pan and melt, then add the garlic, broth, honey, rice vinegar, and soy sauce; stir to combine. Bring sauce to a boil. Add chicken back in the pan, and simmer 3-4 minutes until the sauce reduces and thickens. Sprinkle with sesame seeds and red pepper flakes (if using).
Serve with lettuce leaves and toppings of choice. Enjoy!