01 - Preheat the oven to 400°F. Grease a 9x13 inch baking dish.
02 - Boil pasta in salted water until just al dente. Drain and set aside.
03 - Heat olive oil in a skillet over medium heat. Season diced chicken with salt, pepper, and garlic powder. Sauté until golden and fully cooked, about 5 to 7 minutes. Remove from heat and reserve.
04 - Melt butter in a saucepan over medium heat. Whisk in flour and cook for 1 minute, stirring constantly.
05 - Gradually whisk milk into the roux. Continue whisking until the mixture thickens, about 3 to 5 minutes.
06 - Remove the saucepan from heat. Stir in cheddar and mozzarella cheeses, Dijon mustard, paprika, and dill. Season the sauce with salt and pepper to preferred taste.
07 - In a large mixing bowl, combine the cooked pasta, chicken, cheese sauce, and chopped dill pickles. Mix thoroughly.
08 - Spread the pasta mixture evenly in the prepared baking dish.
09 - Mix crushed pickle chips, panko breadcrumbs, and melted butter in a bowl until well combined.
10 - Evenly distribute the crust mixture over the pasta. Bake for 20 to 25 minutes until the surface is golden and the casserole is bubbling.
11 - Allow the dish to cool for 5 minutes before serving. Garnish with additional fresh dill if desired.