First you must make the sweet and sour sauce. In a jar, combine the tamari, mustard, 3 Tbsp water, sesame oil, and maple syrup. Cover and shake vigorously. Refridgerate until needed(lasts up to 3 months). Shake well before using.
Now, cut the broccoli into florets and peel and slice the stems into coins about 1/2 inch thick. Take the core from the bell pepper and julliene into strips about 1/4 of an inch thick. Cut the carrots in half (cross wise, not length wise), then julliene them as well. Drain and rinse the water chestnuts.
Cook rice noodles according to directions on the package. When they are almost done, boil the 1/3 c water in a wok or large skillet on high heat. Add the broccoli, bell pepper, and carrots. Cover and cook on high until just short of done, about 2 minutes. Stir in the water chestnuts, 5 to 7 Tbsp sweet and sour sauce, rice noodles, and I like to put 1/4 tsp crushed red pepper in. It makes it a little spicy. Cook, stirring constantly until the broccoli is crisp-tender, 1 to 2 more minutes. Taste and add more sauce if needed as well as Tamari.
Enjoy! And if anyone has other good Japanese recipes please email me with them.