Place the chicken and 1/4 cup cornstarch in a resealable plastic bag, shake to coat evenly.
Heat the vegetable oil in a large pan over high heat.
Add the chicken to the pan in a single layer and season to taste with salt and pepper.
Cook for 3-4 minutes per side or until browned. Cook in multiple batches if needed.
Remove the chicken from the pan and place on a plate lined with paper towels.
Add the broccoli, celery and bell pepper to the pan. Cook for 4-5 minutes or until vegetables are tender. Season with salt and pepper to taste. Stir in the baby corn. Add the garlic and cook for 30 seconds more.
Add the chicken back to the pan with the vegetables.
In a small bowl, whisk together the chicken broth, soy sauce, oyster sauce, rice vinegar, honey, chili paste and 2 teaspoons cornstarch.
Pour the sauce over the chicken and vegetables; bring to a simmer. Cook for 1-2 minutes or until sauce has thickened. Serve immediately over rice if desired.