In a large mixing bowl, combine the flour, cornstarch, salt, and black pepper. Mix well.
Dip each piece of chicken in the beaten eggs, then coat thoroughly with the flour mixture. Shake off any excess flour.
In a frying pan, heat the vegetable oil over medium-high heat until it reaches 350°F (175°C).
Carefully add the chicken pieces to the hot oil in batches, making sure not to overcrowd the pan. Fry for about 5-7 minutes, until golden brown and cooked through.
Once cooked, place the chicken on a plate lined with paper towels to absorb excess oil.
In another mixing bowl, whisk together the mayonnaise, sweet chili sauce, sriracha, and lime juice until smooth.
Drizzle the Bang Bang sauce over the crispy chicken, or toss the chicken in the sauce to coat evenly.
Garnish with chopped green onions before serving.