Start by assembling the ingredients needed for the basic soup. You'll need about 1/3 cup (70 g) flour, 4 ounces (110 g) butter, 1 cup (235 mL) chicken broth or stock, 4 ounces (110 g) diced onions (about 1/2 large yellow onion), 2 oz. (55 g) celery, 2 oz. (55 g) leeks, 7 cups (1.65 L) whole milk (not pictured). You'll also need to have 12 to 16 ounces (340 to 450 g) button mushrooms, 1/4 teaspoon (0.4 g) dried, ground tarragon, 1/2 cup (120 mL) heavy cream, lemon juice, salt, and pepper for finishing the recipe.
Start by washing the leeks. Often, mud and dirt will get trapped in the layers of the leek, so special care should be taken to wash them thoroughly. The easiest way to do this is simply to break the leeks apart under running water and use your fingers to help wash the dirt away. The celery should also be rinsed and deveined.
Chop off the green tops, leaving the base of the leeks to make a total of about 2 ounces. Dice the leeks, celery, and onion. This combination of vegetables is often called a white mirepoix (while a "normal" mirepoix substituting carrots for the leeks).
Melt the butter in a 3-1/2 quart or larger pot over low heat.
Add the onions, celery, and leeks to the melted butter and turn the heat up to medium-low. Stir the white mirepoix as it sweats until the onions are translucent, about 6 minutes.
Add the flour to the mixture and continue to stir and cook over medium-low heat. Cook for about twelve minutes.
The flour mixture should have taken on a slightly yellowed appearance at this point.
While stirring, slowly pour the chicken broth into the pot. After all the broth has been incorporated into the flour mixture, keep stirring until there are no more lumps.
Now, slowly add milk to the pot. To keep from forming lumps, you'll want to pour a little milk at a time. Slowly pour about 1/2 cup milk into the pot and stir until it's been fully integrated into the flour. Repeat with 1/2 cup milk at a time until four cups of milk have been stirred in. At that point, it should be fine to pour in the last three cups of milk without lumps forming.
Bring the soup to a full boil, then simmer for 45 minutes (until smooth and thickened).
In the meantime, prepare the ingredients for the final part of the recipe: 12 to 16 ounces (340 to 450 g) button mushrooms, 1/4 teaspoon (0.4 g) dried, ground tarragon, and 1/2 cup (120 mL) heavy cream. Lemon juice, salt, and pepper will be used for seasoning as well.
Wash the mushrooms.
Cut all the mushrooms into a fine dice. It's important to get the mushrooms cubes to be as uniform as possible so they will cook evenly. It also makes the final soup more attractive.
Set the mushrooms aside as the soup simmers.
Add the 1/4 teaspoon tarragon to the soup and stir in.
Add all the diced mushrooms to the soup and stir until evenly mixed.
Simmer for 10 minutes.
Turn off the heat and stir in 1/2 cup heavy cream. Add lemon juice, salt, and pepper to taste. For my ingredients, I found that 1 teaspoon lemon juice, 1 teaspoon table salt, and 1/2 teaspoon fresh ground pepper was just right.}?>
Cream of Mushroom Soup (makes about 3 quarts, approx. 10 servings)
|4 ounces (110 g) butter||melt||sweat 6 min.||stir in and cook 12 min.||gradually stir in||stir in 1/2 cup at a time until 4 cups||stir in rest of milk||bring to boil||simmer 45 min.||fold in, simmer 10 min.||stir in, remove from heat||season to taste|
|4 ounces (110 g) diced onions||wash and dice|
|2 oz. (55 g) celery|
|2 oz. (55 g) leeks|
|1/3 cup (70 g) flour|
|1 cup (235 mL) chicken broth or stock|
|7 cups (1.65 L) whole milk|
|12 to 16 ounces (340 to 450 g) button mushrooms||dice|
|1/4 teaspoon (0.4 g) dried, ground tarragon|
|1/2 cup (120 mL) heavy cream|