This rich, earthy soup has but 100 calories per serving if made with non-fat milk.
PLACE THE MILK, ONION, peppercorns, salt and bouquet garni in a saucepan and bring slowly to a boil. Form a smooth paste of the rice flour and the cold milk. Put into the just-boiling milk and stir briskly until there are no lumps. Simmer over very low heat for 20 minutes. Meanwhile, cut off the tough ends of the mushroom stems. Reserve a few mushroom slices for garnish and chop the remaining mushrooms coarsely, then place in a food processor with a steel blade and chop as finely as possible. Strain the milk mixture through a fine sieve back into the saucepan; add the chopped mushrooms and continue simmering 5 minutes. Add the cream and Madeira, if you wish, and serve in hot bowls, garnished with a slice of mushroom.