Pierogis are from my father's side of the family! We are Czech mostly that side. I think that King Arthur recipe looks great, in general they always offer really good recipes.
Back in the day when ground turkey was new and cheap, I used to make a lot of pierogis with them. Also "turkey ball curry" which is much better then it sounds. But I was young and poor and it was good food.
We usually serve "white fry" with them, chop about half cabbage into thin strips. Take one apple (something like granny smith is best) cored, cut into thin slices, can leave skin on. Cut one onion into thin rounds. Stir fry all together with butter if you want or oil if you don't. Add some celery seeds into the last five minutes or so. That big mound of cabbage will surrender into a reasonable portion.