1. Place the chicken breasts in a shallow dish or large zip-top bag. Pour in the dill pickle juice and buttermilk, turning the chicken so it is mostly submerged. Cover and refrigerate for at least 30 minutes and up to 4 hours to brine.

2. When ready to cook, preheat the oven to 400°F (200°C). Line a large baking sheet with parchment paper or lightly grease it.

3. In a shallow bowl, combine the panko breadcrumbs, 3/4 cup finely grated Parmesan, garlic powder, onion powder, paprika, 1/2 teaspoon kosher salt, 1/2 teaspoon black pepper, and 1 tablespoon of the chopped fresh dill. Stir until everything is evenly mixed.

4. Remove each piece of chicken from the brine, letting excess liquid drip off. Press the chicken firmly into the breadcrumb mixture, coating both sides and pressing so the crumbs adhere well. Place the coated chicken on the prepared baking sheet in a single layer.

5. Drizzle the tops of the breaded chicken evenly with the olive oil or melted butter. Bake for 18–22 minutes, or until the chicken is cooked through, the crust is deep golden, and an instant-read thermometer inserted into the thickest part registers 165°F (74°C).

6. While the chicken bakes, make the sauce. In a medium bowl, whisk together the mayonnaise, sour cream or Greek yogurt, finely chopped dill pickles, dill pickle juice, Dijon mustard, minced garlic, remaining 1 tablespoon chopped fresh dill, 1/4 teaspoon black pepper, and a pinch of kosher salt. Adjust seasoning to taste and add a splash more pickle juice if you prefer a thinner sauce.

7. Once the chicken is done, transfer it to a serving platter. Spoon generous dollops of the creamy dill pickle sauce over each piece. Sprinkle with the 2 tablespoons finely grated Parmesan and top with dill pickle slices and extra fresh dill if desired. Serve immediately while the chicken is hot and crispy and the sauce is cool and tangy.