Prep Your Ingredients. Begin by gathering and prepping all your ingredients. This includes measuring out the bourbon, mincing the garlic, and slicing the chicken into bite-sized pieces.
Marinate the Chicken. In a bowl, combine the bourbon, soy sauce, brown sugar, ginger, garlic, and red pepper flakes. Mix well. Place the chicken pieces in a Ziploc bag or a container with a lid and pour the marinade over them. Seal and refrigerate for at least 30 minutes, allowing the flavors to meld.
Sauté the Chicken. Heat a large skillet or pan over medium-high heat. Add vegetable oil and let it get hot. Remove the chicken from the marinade, reserving the marinade, and add it to the hot skillet. Sauté the chicken until it's browned and cooked through, about 5-7 minutes.
Make the Sauce. In the same skillet, add the reserved marinade and cornstarch. Stir well and let it simmer until it thickens into a glossy sauce, about 2-3 minutes.
Add Vegetables. Toss in the bell peppers and green onions. Sauté for another 2-3 minutes until they are slightly tender yet still crisp.
Finish and Serve. Return the cooked chicken to the skillet and stir to coat it with the sauce. Let it simmer for a couple of minutes to heat everything through. Serve your Bourbon Chicken over a bed of steamed rice and garnish with sesame seeds and chopped green onions.