Pat the 2 pounds chicken tenderloins dry with paper towels.
Sprinkle the chicken evenly on both sides with 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.
Melt 3 tablespoons unsalted butter in a frying pan over medium heat. Add 2 cups panko bread crumbs and cook for 5 minutes until the breadcrumbs turn a light golden brown color.
Transfer to a shallow bowl like a pie plate and stir in the ¼ cup grated parmesan cheese.
Place a cooling rack on a baking sheet.
Whisk together the 1 cup sourdough starter, 2 tablespoons brown sugar, 1½ teaspoons of kosher salt, 1 teaspoon parsley, 1 teaspoon sage, 1 teaspoon thyme, 1 teaspoon garlic powder, ½ teaspoon smoked paprika, and ½ teaspoon ground black pepper in a shallow dish. I like to use a pie plate.
Dip the chicken into the batter.
Transfer chicken to the breadcrumbs and toss to coat. Pressing down lightly to help the breadcrumbs adhere.
Preheat oven to 425°F (220°C).
Place chicken on the baking sheet and spray lightly with oil. Flip and spray the second side with oil. Bake for 18 to 22 minutes until the internal temperature is 165°F (74°C).