Pat the 2 pounds chicken tenderloins dry with paper towels.
Sprinkle the chicken evenly on both sides with about 1½ teaspoons kosher salt.
Place the chicken on a cooling rack placed inside a sheet pan and refrigerate the chicken uncovered for 6 to 8 hours.
Remove the chicken from the refrigerator 20 minutes before frying.
Batter
Pour the 1 cup sourdough discard into a shallow dish. I like to use a pie plate.
In a separate shallow dish, whisk together the 1 ½ cups all-purpose flour, 2 tablespoons brown sugar, 1½ teaspoons kosher salt, 1 teaspoon chili powder, 1 teaspoon garlic powder, 1 teaspoon dried thyme, 1 teaspoon dried oregano, 1 teaspoon celery salt, ½ teaspoon cayenne pepper, ½ teaspoon smoked paprika, ½ teaspoon ground mustard, ½ teaspoon ground ginger, and ½ teaspoon ground black pepper.
Dip the chicken into the sourdough discard and then coated it with the seasoned flour. This method can be a bit messy. The best way to minimize the amount of coating that sticks to your fingers is to use one hand for the dry mixture and one hand for the wet mixture. Use your left hand to coat the chicken with the sourdough mixture and place it in the seasoned flour mixture. Use your right hand to coat the chicken in the seasoned flour mixture.
Place the chicken on a foil-lined pan while you follow the same process to coat the remaining chicken.
Allow the chicken to rest for fifteen minutes so that the flour absorbs the liquid and better adheres to the chicken.
Frying
Pour the oil into a frying pan until it is about one inch deep.
Heat the oil over medium-high heat until it begins to shimmer and reaches 350 degrees Fahrenheit.
Working in small batches, place the coated chicken strips in the hot oil without crowding them too closely together, you don't want the temperature of the oil to drop too low. I usually split my chicken into three batches. Cook until golden brown on both sides. Approximately 2-4 minutes per side.
Notes
Dry the chicken with a paper towel before dipping it in the batter, to really help it adhere.If you like spicy chicken, try adding hot sauce to the sourdough batter.Don’t overcrowd your pan when frying.Cover the pan with a splash guard to minimize the amount of oil splatter.Storage: Store any leftovers in an airtight container and refrigerate for 3-4 days.To Reheat: To reheat the chicken tenders place them in a 350°F (177°C) oven for 15-20 minutes.