Prepare the Chicken: Cut the chicken breasts into 1-inch cubes.
Season the Chicken: Sprinkle the chicken with salt, pepper, and garlic powder (or minced garlic).
Sear the Chicken: In a large skillet, heat 1 tbsp olive oil over medium-high heat. Add the chicken and sear until golden brown on all sides. Remove the chicken and set aside.
Make the Sauce: In the same skillet, add the soy sauce, orange marmalade, brown sugar, rice vinegar, honey, sriracha, and bourbon. Stir and bring to a simmer.
Thicken the Sauce: In a small bowl, mix the cornstarch with water to create a slurry. Stir this mixture into the sauce and cook for 2-3 minutes, or until the sauce thickens.
Combine in the Crockpot: Transfer the seared chicken to the Crockpot. Pour the sauce over the chicken, stirring to coat evenly.
Cook: Cover and cook on low for 4-5 hours, or until the chicken is tender and cooked through.
Garnish: Just before serving, garnish the dish with toasted sesame seeds, sliced green onions, and orange slices, if desired.