During winter I often think wistfully of cream soups and the days before I gave up dairy. I adjusted my old recipe to try and recreate the flavor without the milk products. It's easy to adjust, so play with it and tell me what you think.
In a small soup pot, put the water on to boil (just enough to hold your veggies). As soon as your water begins to boil, add the celery and other vegetables. Return to a boil and then lower the heat to a medium simmer until the veggies are cooked soft. Then drain, but keep the water. Give the drained veggies a few good mashes to help thicken the soup.
While the vegetables are boiling, melt the margarine in a large soup pot. Saute the onions on med-high heat. Once they are soft, add the mushrooms and the garlic. Saute until the mushrooms release their liquid.
Add the oil to your onion-mushroom mixture (as needed). Slowly build a rue around the onion-mushroom mixture by adding sifted flour slowly. As it thickens, add the water from the boiled celery mixture a ladle at a time, and then thicken some more. Continue until you have a thick enough rue for your liking and you are ready to add the soy milk.
Add in about half of the soymilk, whisking to distribute the thick saute mixture. When you have enough liquid, add the cooked celery and potatoes. Continue adding celery water and then milk, balancing it out to your tastes.
Once you have the thickness and amount of soup you want, season your soup. I added garlic salt, white pepper, salt, black pepper and a small bit of Greek oregano. Add the spices slowly, mixing and tasting until the soup is balanced well.
Let the soup sit at a small simmer for about 15 minutes to combine. Serve with rustic bread.