Polish Pierogies with Cabbage and Mushroom Sauce
You can make the pierogies ahead and freeze them after boiling them in Step 4. Then just fry the pierogies when you're ready to serve them.
To save time you can cook the cabbage the day before and then just reheat and squeeze dry. If the sauce is too thick, delude with water, if too thin, thicken with more potato starch.