First you make the soup base: Chop 2 parts onions and 1 part each celery and carrots (optional garlic to taste) Then sweat (cook on medium heat until translucent) these vegetables in some oil or margarine.
Add vegetables you like in soup, I chose mushrooms but you could add anything. If you pick something that cooks quickly or loses color (like broccoli or leafy greens) then wait and add these later. Cook these vegetables for a while.
When the vegetables are done add however much vegetable stock you want. You can add water an bullion cubes or you can add stock from a box.
Your soup should now be salty and have vegetable flavors, but we want to make it taste more complex. Salt vinegar and sugar should be in just about everything and so since we have salt we need to add vinegar and sugar. I add about twice as much vinegar as sugar and then taste. If it tastes flat add more salt, if it tastes too tart add more sugar and salt if it tastes too sweet add more vinegar and salt if it tastes too salty add more vinegar and sugar. Dont use white vinegar because it tastes bad, but any other kind of vinegar will do. You can also add any spices you like (oregano, thyme, basil, sage ect... I added sage and thyme). I also threw in some liquid smoke because I love that stuff, but its not nessecary (and only add a little because it is strong)
When the soup tastes good you are ready to finish it.
The "meat" in the stroganoff was seitan, which I make from high gluten wheat flour (you can buy it at harvest in bulk). Add salt and pepper to the flour and then mix up a slightly smaller volume of liquid composed of 2 parts water 1 part soy sause (or omit and add some salt) 1 part vinegar. Taste the liquid to make sure it is good and then mix the flour with the liquid. This mass should be stretchy and moist and look kind of like brains.
Tear off small (1/2 ping pong ball) chuncks of the seitan and throw it in the now boiling soup. The seitan will expand to roughly double in size, cook it for 10 more minutes and pull out a chunk. It is done if it is slightly chewy but not like bubble gum. then you can throw in any leafy greens of veggies that cook fast.
As those are cooking you want to mix about 1/5 the soups volume of soy milk with enough corn starch to thicken it (directions on the corn starch box) as the corn starch heats up it will thicken, and it will continue to thicken as the soup cools. Once it is about as thick as you like the dish is finished.