TRUE CONFESSION: Put this spicy peanut sauce on anything -- a piece of shoe leather, marshmallows, or even the cauliflower I dislike so much -- and I will eat it. Put it on something I do like, and I will lick my plate clean. Peanuts and Japanese buckwheat noodles (soba) have a natural affinity, but this dish will be just as good with spaghetti, or whole wheat penne, or just about any type of noodle or pasta. One tip: don't stir-fry the vegetables for more than a minute. You'll like the crunch of barely-cooked Napa cabbage with the chewy soba. The recipe makes far more peanut sauce than you'll need. Store the extra in the refrigerator for up to two weeks, and use it as a dip or a dressing. You can thank me later.