Dole Yeast
From FenWiki
Dole Yeast originates in Larry Niven Known Space series of novels and stories. It will grow on just about anything, including minimally processed sewage. The wonderful thing about it is that it provides all the nutrition that a human body needs. The reason no one wants to eat it is that it is nearly tasteless, and makes wet cardboard appear a gourmet dish. Attempts to make it more tasty with plant pot-grown herbs, or spices, are very rarely successful - some claim to have 'secret recipes'. Living on this is a strong incentive to find some source of more attractive food.