The dough is ready to use right away but if you are not forming the pierogies immediately, wrap in plastic and refrigerate the dough for at least 2 hours or up to 2 days. If you're not serving all the pierogies at once you can freeze them. If desired, you can also pan-fry the pierogies. When pan-frying the frozen pierogies, heat a skillet on medium heat with a tablespoon of olive oil. Place the pierogies in the skillet, cover and pan-fry for 3 minutes. Add a tablespoon of water so that it sizzles, cover immediately and cook for 2 to 3 minutes. Flip and repeat.