In a medium bowl, combine cornstarch, gluten-free flour, salt, and pepper. In another bowl, whisk eggs and soy sauce.

Dip chicken pieces into the egg mixture, then dredge in the cornstarch mixture to coat evenly.

Heat oil in a large skillet or wok over medium-high heat. Fry chicken pieces in batches until golden brown and crispy, about 4–5 minutes per side. Transfer to a plate lined with paper towels.

Wipe the skillet clean and add sesame oil. Sauté garlic, ginger, and red pepper flakes for 30 seconds until fragrant.

In a small bowl, whisk together broth, soy sauce, rice vinegar, brown sugar, and hoisin sauce. Add to the skillet and bring to a simmer.

Then stir in the cornstarch slurry. Cook until the sauce thickens, about 2–3 minutes.

Return fried chicken to the pan, tossing to coat evenly with sauce. Garnish with sliced green onions and sesame seeds. Serve hot and enjoy.