Some folks may not know what frozen pierogis are.
I have heard of them though never eaten one.
From King Arthur Baking:
Pierogi, boiled dumplings, are very flexible and can be stuffed with a number of savory or sweet fillings, including potato and cheese (below); sauerkraut, cabbage, spiced meats, and even fruits and berries.
King Arthur Baking suggests to cooked in a large stockpot of boiling salted water.
Then sauté the shallots or onion in the butter in a large skillet until the onion begins to brown.
Add the drained pierogi and cook until browned and crisped.
Serve hot with additional sour cream, applesauce, or other condiments.
These pierogies sound yummy!
For the recipe:
https://www.kingarthurbaking.com/recipes/homemade-pierogi-recipe