If you’re using store bought or packaged dumplings or potstickers, you can use any variant of your choice. If you’re making the dumplings from scratch at home, it makes sense to freeze them first, and then use them.  You can try out quite a few dumpling fillings based on what you have at hand. Chopped veggies like carrots, bell peppers and cabbage are some classics, and you can also try your hand at a spicy chicken filling if you want to.