Crockpot Pierogi Casserole with Kielbasa Creamy, cheesy comfort in a slow cooker, pierogies, kielbasa, and caramelized onions all in one cozy dish. Ingredients: 1 package (16 oz) frozen potato and cheese pierogies 1 lb kielbasa, sliced into rounds 1 small onion, thinly sliced 1 tablespoon butter 1 can (10.5 oz) cream of mushroom soup 1/2 cup sour cream 1/2 teaspoon garlic powder 1/2 teaspoon black pepper 1 cup shredded cheddar cheese Chopped parsley for garnish Instructions: In a skillet, melt b