**Prepare the chicken**
Toss the chicken pieces with 2 tablespoons of cornstarch in a mixing bowl until evenly coated.
**Sear the chicken**
Heat the vegetable oil in a large skillet or wok over medium-high heat. Add the chicken in a single layer and cook for 5β7 minutes, turning occasionally, until golden brown and cooked through. Remove the chicken from the skillet and set aside.
**Make the sauce**
In the same skillet, add the bourbon, soy sauce, brown sugar, ketchup, apple cider vinegar, garlic, ginger, and crushed red pepper flakes (if using). Whisk the ingredients together and bring to a simmer.
**Thicken the sauce**
In a small bowl, mix the water and 1 teaspoon of cornstarch to create a slurry. Slowly whisk the slurry into the sauce. Simmer for 2β3 minutes until the sauce thickens and becomes glossy.
**Combine and coat**
Return the cooked chicken to the skillet. Toss to coat the chicken evenly in the sauce and let it simmer for another 2β3 minutes to absorb the flavors.
**Serve**
Serve the bourbon chicken hot over steamed rice or alongside your favorite vegetables. Garnish with chopped green onions if desired.