I found this soup on the internet on a vegan website. It's vegan, fat free and low in calories. I've modified it a bit. The original recipe included 1/3 cup small pasta and 1 tsp mellow miso. Nutritional yeast is pretty strong so novices should add 1/2 the amount and taste the soup first.
Weekly cooking for my mother was becoming mundane, so I branched out to something new. I had no trout, nor did I have time to follow the Brown sauce recipe from Commander's Palace. This is the yummy result.