Two friends of mine and I typically get together in November and make 30-33 dozen perogies. The "chief" perogie maker has us boil them (1 doz at a time), for a minute, drain, toss in a stainless bowl with 1 tsp of butter, and then package in a zippie, lay them flat (in the zippie) on a cookie sheet, flash freeze. The butter keeps them from sticking and when you thaw them (10 minutes in the microwave on defrost setting), you can pan fry them for about 4-5 minutes (in butter, naturally) on each side on medium to medium high. I usually start sweating the onions when the perogies go in the microwave.