The best way to know for sure that your miso soup is vegan is to make your own at home. This recipe only has 5 ingredients and can be made in as little as 5 minutes. Who would have thought that homemade miso could be so simple?The serving size is good for one person but is slightly larger than what you would get in a restaurant. Enjoy by yourself or split with one other person. The recipe can also be doubled or tripled if you're catering for a crowd.