Combine 2 cups of flour, salt, and water in a large mixing bowl. Mix with a wooden spoon until it turns into a lump. Then knead it by hand for a few minutes until the dough gets a little softer. Put it in a plastic bag to keep it from the air and let it sit for 10 to 30 minutes on the kitchen counter.
Take the dough out of the plastic bag. It will be a little softer and moist and easier to handle. Knead it for 5 to 7 minutes, until it’s smooth and elastic.
Place the dough on a cutting board dusted with a bit of flour and divide it into 2 equal pieces. Put one half into the plastic bag to keep it from getting dried out as your work on the other half.
Cut the piece of dough into 8 equal sized pieces. Roll each piece out with a rolling pin into 5½ to 6 inch round circle disks. They should be a little thinner on the edges than in the middle, because we’ll eventually be pinching the edges together when we make mandu, so you don’t want them too thick and doughy.
Take the second half out of the bag and make mandu wrappers out of it using the same method.
Use them right away to make mandu, or freeze them for later.