Prep the ingredients per the instructions above.
Season the chicken with salt and pepper, then submerge in the buttermilk. Mix together the flour, cornstarch, garlic powder, paprika, and oregano. Season with salt.
Heat the oil in a large skillet or pot over medium heat to 325℉ (162℃).
Dip the chicken into the flour mixture, then into the buttermilk, then back into the flour mixture to coat very well on all sides.
Fry the chicken until golden brown on both sides to an internal temperature of 160°F (71℃) using a thermometer (in batches if needed so the oil isn't overcrowded). Place on a paper towel-lined plate to drain the excess oil. Season with a small amount of salt right away.
Layer the bun with lettuce, tomato, chicken, buffalo sauce, and blue cheese.
Serve with celery sticks, ranch, and kombucha.