How to Prepare Stir-Fry Udon Udon noodles is one of my favorite food because they have a great chewy texture. It’s quite easy to prepare stir-fry udon noodles. The main ingredients are onions, frozen udon noodles, bok choy and shiitakes. I usually buy them at PX Mart and Taisuco. I also need a few seasonings: salt, soy sauce and pepper. How to cook it? First off, I slice onions, bok choys and shiitakes, heat the oil in the frying pan, add the greens, two tablespoons of soy sauce and water. Secondly, I cook udon noodles according to package directions. Finally, I season the noodles with salt and pepper. That’s it.