Begin by placing the cut-up chicken pieces in a large mixing bowl. In a separate bowl, whisk together the buttermilk and the beaten egg. Pour this mixture over the chicken, ensuring each piece is thoroughly coated. Cover the bowl with plastic wrap and refrigerate for at least 2 hours, or ideally overnight.
In a shallow dish, combine the all-purpose flour with paprika, garlic powder, ground white pepper, celery salt, black pepper, dry mustard, kosher salt, onion powder, thyme, basil, oregano, ginger, and MSG (if using). Mix well to ensure an even distribution of spices.
Once the chicken has marinated, remove it from the refrigerator. Take each piece of chicken and let any excess buttermilk drip off before dredging it in the seasoned flour mixture. Make sure each piece is well-coated, then set it aside on a wire rack.
In a deep fryer or heavy-bottomed pot, pour in enough vegetable oil to submerge the chicken pieces halfway. Heat the oil to 350°F (175°C). Use a cooking thermometer to monitor the temperature.
Carefully add a few pieces of chicken to the hot oil, making sure not to overcrowd the pot. Fry for about 12-15 minutes, turning occasionally, until the chicken is golden brown and cooked through.
Continue frying the remaining chicken in batches. Once all the pieces are done, let them sit for a few minutes to cool slightly before serving.
