Toss chicken with 3 tablespoon cornstarch, salt and lemon pepper until evenly coated.
In a large 12 inch skillet, heat 3 tablespoon oil over medium-high heat. Cook chicken for 1 ½ minutes per side or just until beginning to brown. Remove to a platter and repeat cooking chicken pieces in batches. (The chicken doesn't have to be cooked through.)
To the skillet add garlic, cooking for 1 minute or until fragrant. Next, add brown sugar, apple juice, chicken stock, soy sauce, ketchup, brown sugar, bourbon, vinegar, onion powder, ginger and red pepper flakes. (You may use water, apple juice or additional chicken stock in place of bourbon.)
Add chicken back to skillet, mxi well. Reduce heat to medium-low and let simmer uncovered for 15-20 minutes or just until chicken is cooked through and sauce has slightly thickened.
Serve immediately over rice garnished with green onion.
To thicken sauce further, at the end of cooking. Dissolve 1 tablespoon cornstarch in 1-2 tablespoon cold water. Stir until completely dissolved. Increase heat, and mix cornstarch slurry into sauce. Mix well, cook just until sauce has thickened slightly. Repeat process, if desired, until thickened to your taste. (You may opt to skip this step altogether.)