Prepare the Marinade: In a medium bowl, whisk together bourbon, brown sugar, soy sauce, apple cider vinegar, and chicken broth. Add minced garlic and grated ginger, whisk until dissolved.

Marinate the Chicken: Place chicken breasts in a resealable bag or dish. Pour marinade over, ensuring full coverage. Seal/cover and refrigerate for at least 1 hour or overnight.

Preheat the Griddle: Heat the Blackstone griddle over medium-high for about 5 minutes. Add vegetable oil to prevent sticking.

Season the Chicken: Remove chicken from marinade, reserving it. Season with salt and pepper.

Cook the Chicken: Grill chicken for 5-6 minutes per side until golden brown and internal temperature reaches 165°F (74°C).

Prepare the Sauce: Strain reserved marinade through a sieve into a saucepan. Bring to a gentle boil.

Thicken the Sauce: Combine cornstarch with water to create a slurry. Whisk into boiling marinade until thickened, about 2-3 minutes.

Glaze and Rest: Brush thickened sauce over cooked chicken. Allow to rest for a few minutes.

Slice and Serve: Slice chicken and drizzle with additional sauce. Garnish with green onions and sesame seeds. Serve hot.