Prepare the sauce by whisking chicken broth, hoisin sauce, sesame seed oil, honey, rice wine vinegar, minced garlic, cracked black pepper, chili powder, and grated ginger in a medium bowl. Set aside.

Coat the chicken by mixing cornstarch, salt, and additional cracked black pepper in a large bowl. Cut chicken thighs into bite-sized pieces and coat them in the mixture.

Heat a large skillet over medium-high heat and add vegetable oil. Sear the coated chicken for 5-7 minutes until browned and cooked through, then remove from the pan.

Sauté the vegetables in the same skillet, adding minced garlic, grated ginger, green bell pepper, onion, and celery. Cook for 5-7 minutes until tender.

Combine the chicken with sautéed vegetables and pour the prepared sauce over them. Simmer for 3-5 minutes until the sauce thickens.

Serve the Black Pepper Chicken over steamed rice or lo mein noodles. Garnish with cracked pepper or sesame seeds if desired.