Grease your crockpot with cooking spray to prevent sticking.
Place half of the frozen pierogi in the bottom of the crockpot.
1 (28 ounce) frozen pierogi
Over the pierogi, layer half of the sliced kielbasa, chopped onion, and chopped green bell pepper.
1 pound kielbasa, 1 medium onion, 1 medium green bell pepper
Repeat the pierogi, kielbasa, onion, and bell pepper layers.
1 (28 ounce) frozen pierogi, 1 pound kielbasa, 1 medium onion, 1 medium green bell pepper
In a bowl, whisk together the cream of mushroom soup, cream of chicken soup, sour cream, milk, garlic powder, and black pepper.
1 (10.75 ounce) condensed cream of mushroom soup, 1 (10.75 ounce) condensed cream of chicken soup, 1/2 cup sour cream, 1/4 cup milk, 1 teaspoon garlic powder, 1/2 teaspoon black pepper
Pour the soup mixture evenly over the pierogi and kielbasa in the crockpot.
1 (28 ounce) frozen pierogi, 1 pound kielbasa
Cover and cook on low for 6-8 hours or on high for 3-4 hours.
During the last 30 minutes of cooking time, sprinkle the shredded cheddar cheese over the casserole.
1 cup shredded cheddar cheese
Replace the lid and let the cheese melt completely.
Serve hot and enjoy!