We have a Polish & Greek place by us (don't ask), and theirs are always boiled.
They are delicious that way (usually topped with bacon and sour cream)...
Personally I always grew up w/
them boiled then sauteed, which is my favorite.
cooking.stackexchange.com/users/6791/Rikon
The most common way here in Poland to prepare them is to boil them.
Put them into boiling and salted water, wait until they start floating on the surface and then boil for 2-3 minutes
(longer if they are frozen).
cooking.stackexchange.com/users/2889/Paweł
My Polish mother-in-law boils them.
The sweet ones are usually served with a bit of yogurt or sour cream, and the savory ones are often fried (after boiling) until golden, and served with onions and bacon.
cooking.stackexchange.com/users/1148/Chris Cudmore
My babcia (grandmother, she came to the states in '49) boils them after assembly.
If she's serving them right away, she browns them in some butter.
Otherwise, she packages them up in ziplock bags and freezes them.
Packaged pierogi are probably already boiled.
I would thaw them and saute in a little butter until golden brown and warm through.
cooking.stackexchange.com/users/5646/Adam Jaskiewicz
First boil them.
Remove from water and brown some butter and pour the butter over the pierogi and toss in a large bowl.
Later you can either fry them or warm them in the microwave.
cooking.stackexchange.com/users/68272/Rusty
My grandmother, who is from Poland, simmered them in boiling salted water and then drained them.
She smothered them in butter that had been browned, this was how my mother taught me.
Not sure if this is the authentic way
but it is what was passed down three generations.
This process is used for the potato cheese mix as well as the fruit pierogi, both being covered with browned butter
cooking.stackexchange.com/users/63790/Phyllis Knapik
I've been buying pre-packaged pierogi from Trader Joe's and local Polish delis. But I can't seem to get a straight or consistent answer on how you are  supposed  to cook them. Should you steam pierogi, boil them, or saute them with butter?
What is the authentic way to cook pierogi?
cooking.stackexchange.com
<boiling><sauteing><steaming><dumplings><polish-cuisine>
cooking.stackexchange.com/questions/16641
cooking.stackexchange.com/users/6943/Shel
The traditional way in Poland is to boil them in salted water, although packaged pierogi may already have been boiled. When serving right away, you can brown them in some butter and serve with onions and bacon, or serve with a bit of yoghurt or sour cream. They are generally boiled and then sauteed or fried. However, packaged pierogi are probably already boiled.
They are boiled and then sauteed. You can boil them and fry them before serving with sour cream, onions and bacon. They are probably already boiled.