Two 16-ounce packs of frozen potato-and-cheese pierogi layered twice with sliced kielbasa and thinly sliced onion in a greased slow cooker.
A cup of broth around the sides, three and a half hours on LOW, then cream cheese and sour cream folded through with cheddar and a final twenty to thirty minutes under the lid.
Why This Recipe Works
- The pierogi go in frozen. It is the single thing keeping them intact — thawed, they are soft parcels of potato that fall apart in the first hour of any slow cook.
- Only one cup of broth for two pounds of pierogi. They release moisture as they thaw and the kielbasa renders its own fat; starting wetter than this gives you dumplings in soup.
- The sauce is mixed in a bowl before it goes in. Four ounces of cream cheese dropped cold into a full cooker would sit in lumps; combined with the sour cream first it folds through evenly.
- Fully cooked kielbasa. It is a cured, ready-to-eat sausage, so the four hours are about flavour rather than cooking — it renders its paprika-scented fat down through both layers.
- The cheddar is split. A cup goes into the fold and thickens the sauce; half a cup goes on top for the last stretch and browns lightly under the lid.
How It Is Built, And How It Is Finished
Everything about this casserole is designed to leave the pierogi intact. It is layered rather than mixed, the broth goes around rather than over, and the sauce is folded in only at the end.
Half the frozen pierogi, kielbasa and onion
Straight from the freezer into a greased crock, with sliced fully cooked kielbasa and thinly sliced onion over them. Frozen is not a shortcut — it is what holds the parcels together through four hours.
The same again
A second identical layer. Two shallow layers cook more evenly than one deep pile, and the kielbasa fat renders down through both rather than sitting on top of one.
A cup of broth, poured around the sides
Around, not over. Poured on top it would wash the seasoning off and waterlog the upper pierogi; around the sides it turns to steam, which is what actually cooks them.
The sauce, folded in at three and a half hours
Cream cheese and sour cream stirred together in a bowl first, then folded through with a cup of the cheddar. Mixed in a bowl because cold cream cheese dropped into a cooker never disperses evenly.
The last half cup of cheddar
Over the top, covered for twenty to thirty minutes. That final stretch melts the cheese and finishes the pierogi at the same time.
Scallions at the table, sliced fresh against a very rich dish.
Ingredient Notes
- Frozen potato-and-cheese pierogi
- Two 16-ounce packages, used straight from the freezer. Thawing them first is the surest way to end up with a potato casserole rather than a pierogi one.
- Fully cooked kielbasa, sliced
- Fourteen ounces. Fully cooked is specified — a raw sausage would render very differently and would need cooking through rather than warming.
- Cream cheese, cubed
- Four ounces, cubed and stirred into the sour cream before it goes in. Cold cream cheese added straight to the crock never disperses.
- Sour cream
- One cup, full-fat. It is the body of the sauce and low-fat versions carry more water into a dish that already has plenty.
- Cheddar, divided
- A cup and a half: one cup folded in, half a cup on top. The folded cup thickens the sauce, the top layer melts.
How to Make It
Grease the cooker
Lightly grease a 6-quart slow cooker.
Layer twice
Layer half the frozen pierogi, kielbasa and onion in the cooker, then repeat.
Broth around the sides
Pour the broth around the sides and sprinkle with garlic powder and pepper.
Cook on LOW
Cover and cook on LOW for 3 1/2 hours.
Fold in the sauce
Stir the cream cheese and sour cream together and gently fold them into the casserole with 1 cup cheddar.
Cheese on top
Sprinkle the remaining cheddar over the top and cover for 20 to 30 minutes, until melted and the pierogi are tender.
Serve
Serve with scallions.
Success Tips
- Keep the pierogi in the freezer until the moment they go in.
- Build two even layers rather than one deep one.
- Pour the broth down the side of the crock, never over the top.
- Fold at step 5 with a soft spatula, and stop as soon as it is combined.
- Give the last twenty to thirty minutes under the lid; that is when the pierogi finish.
Serving Ideas
A sharp green salad or quick-pickled cabbage. It is a rich, starchy dish and it wants acidity beside it rather than another side.
Storage and Reheating
Refrigerate
Refrigerate in an airtight container for up to 3 days. The pierogi soften further on standing.
Freeze
Freezing is not recommended. Pierogi that have already been cooked from frozen do not survive a second freeze intact.
Reheat
Reheat gently in a covered pan over low heat with a splash of broth. Stir as little as possible.
Frequently Asked Questions
Can I thaw the pierogi first?
No. Frozen is what keeps them whole through four hours; thawed they are already soft and break apart into dough and potato early on.
My pierogi fell apart.
Either they were thawed or step 5 was stirred rather than folded. Both do the same damage — use a soft spatula and stop as soon as the sauce is through.
Can I use a raw sausage instead of kielbasa?
The recipe specifies fully cooked kielbasa and the timings assume it. A raw sausage would need browning first and would render quite differently.
It came out watery.
Usually extra broth, or the broth poured over the top. One cup around the sides is all it needs — the pierogi and the sausage bring their own moisture.
