- Preheat oven to 375°F and grease the bottom of a medium rectangle casserole dish with cooking spray. Add cream cheese to a saucepan and heat over medium-low heat. When cream cheese is mostly melted, stir in garlic powder, basil, dill, and black pepper. Gradually stir in chicken stock until smooth. Turn heat off.
- Spread perogies in casserole dish and pour cream cheese sauce on top. Evenly top with sliced kielbasa. Cover with aluminum foil and bake for 20 minutes.
- While casserole bakes, stir together breadcrumbs and melted butter in a small bowl. Remove foil and top casserole with shredded cheeses and Panko bread crumbs. Return to oven and bake uncovered 12-15 minutes longer, until Panko is golden brown. Serve hot garnished with green onion.