1Place half a 32-ounce bag of frozen pierogies in a crockpot.
2Chop a kielbasa and add it to the crockpot.
3Sprinkle a cup of chopped onion on top.
4Add half a bag of cheddar cheese.
5Add another layer of frozen pierogies.
6Add the rest of the kielbasa.
7Add the rest of the chopped onion.
8Add the remaining cheddar cheese.
9Combine 1 and 1/2 cups of chicken broth with a 10.5 ounce can of cream of mushroom soup and 1/2 cup of sour cream in a measuring cup. Whisk until well combined.