Mustardy Potato Pierogies

I had gotten some potatoes from my Front Porch Pickings basket. I know that the potatoes were going to be the last thing that would spoil, but today is Sunday and I had more time to play with the dough. Dough is my nemesis. I hate making it, it is always too sticky and flour enjoys messing with my measurements and doughs. I avoid dough making at all costs. At least the dough that needs to be kneaded. (giggle) I enjoyed this dish despite the fact that my kitchen looks like a flour and dirty dish bomb went off. The boy was liking it, but said when he dipped it in some of his salad's balsamic vinegar it became a tasty favorite. I could never count it as a favorite just because of my battle with the dough; also my Lithuanian great grand father always made pierogies with beef and mushroom filling and that is kind of what I think of when I think of pierogies. All in all tasty if someone other than me makes it:). This recipe is from ...