My teenaged son went out to dinner with friends over the weekend and had a Japanese dish with udon noodles. He loved the sauce, but couldn't really tell me much about it except that it was mildly spicy and tasted really good. It was vegetarian. He would like me to make something similar for him, but I'm not the most talented or creative cook and could use some help with a recipe or 2. I'm not familiar with Japanese cuisine (sauces, spices, etc.). Thanks for any help you can give. Oh yes, please, the recipes must be fairly easy (no more than 30-45 minutes tops, from start to finish. Thanks again!