Double check the chicken for any loose bone pieces or excess fat areas and trim as needed. Mix the egg white, pickle juice, soy sauce, baking soda, and the 1/4 cup of cornstarch in a bowl. Season with salt. Add the chicken and stir to combine. Allow to sit in the fridge for an hour.
Mix the slaw ingredients. Cover and set aside in the fridge until ready to use.
Mix the sauce ingredients. Cover and set aside until ready to use.
Bring oil to 375. Mix the flour and cornstarch in a large shallow bowl and season with salt.
Dredge the chicken in the flour mixture and fry until crispy, golden brown, and cooked through. about 3-5 minutes, flipping during cooking.
Toast the buns under the broiler. Start with the bottom bun and top it with the sriracha mayo. Next add the chicken and top with some sauce. Flip the chicken over and add more sauce. Top with the slaw, then the top bun, and serve.