I made this soup tonight and have never had a better cream of mushroom soup, and it was so easy. I have to stay away from milk, but can have cream, and so I did a little experiment. Here's what I used, and a description of how it turned out.
3/4 cup sliced Portabella Mushrooms
3/4 tsp. truffle salt
1 3/4 cup heavy cream
4 tbs. unsalted butter
4 tbs. AP flour
Melt butter in a suitable sauce pan. Add mushrooms. Saute until the mushrooms start to softem, and take on that wonderful cooked mushroom flavor. Add the flour and stir to coat. Let cook for 2 minutes. Stir in the cream to make a thick sauce. Thing with water to desired soup consistency. Stir in the truffle salt. Cover and let simmer for 2 more minutes.
I had cooked up a box of macarony and cheese, without the cheese. I took half of the noodles and combined them with a homemade cheese sauce that came out so very good, along with a half pound of cooked ground beef. I gave that to DW as she didn't want mushrooms.
Before thinning my mushroom soup, I took half of it and combined it with the remaining noodles and cooked ground beef for my supper. I added another half cup of uncooked mushrooms to the remaining soup and simmered over low heat for ten minutes, covered. I then thined the soup with a little water.
I tested the soup and it is creamier than any soup I've ever had, with a rich potabella mushroom flavor, with white truffle accents, and just the right amount of salt. The soup now sits in the fridge. I'll have it for lunch tomorrow. Pure mushroom heaven in a bowl.
Seeeeeeya; Chief Longwind of the North