- 4 tablespoons butter
- 1 cup minced onion or white of leek
- ¼ cup flour
- 1 cup hot chicken stock
- 6 cups milk
- 1 quart fresh mushrooms, trimmed, washed, and diced
- ¼ teaspoon dried tarragon leaves
- ½ cup or more heavy cream, sour cream, or creme fraiche optional
- Salt and freshly ground white pepper
- Drops of lemon juice, optional
- Sprigs of fresh tarragon or slices of sautéed fresh mushroom caps, for garnish
The Soup Base: Sauté the onion or leek slowly with the butter in a heavy-bottomed covered saucepan, for 7 to 8 minutes, until tender and translucent. Blend in the flour and cook slowly 2 or 3 minutes, stirring. Off heat, gradually whisk in the hot stock. Bring to the simmer over moderate heat, and whisk in the milk.
The Mushrooms: Blend in the mushrooms and dried tarragon, and simmer 20 minutes, stirring frequently to prevent scorching. Stir in optional cream, simmer briefly, then season to taste, adding drops of lemon juice if needed. Garnish with tarragon sprigs, or with sautéed mushroom slices floated on each serving.
Nutritional information is based on 1/8 teaspoon added salt per serving, and does not include sprigs of fresh tarragon or slices of sautéed fresh mushroom caps, for garnish.