CREAM OF MUSHROOM SOUP
10 cups sliced mushrooms, 1/4 inch thick (about 2 poun2d)
2 cups celery, 1/4 inch thick (about 3 1/2 large ribs)
1 stick unsalted butter, plus 4 tablespoons, divided
1/2 teaspoon white pepper
4 1/2 tablespoons all purpose flour
6 cups water
1 1/2 tablespoons beef base
1 1/2 tablespoon chicken base
4 cups whole milk
1 1/2 cup half and half
salt and black pepper, to taste
In a large saucepan, combine mushrooms, celery, 1 stick butter and white pepper. Saute over medium heat for 15 minutes or until vegetables have cooked down and released their juices. Remove from heat and set aside. Do not discard liquid.
While mushrooms and celery are cooking, in a large saucepan, melt remaining 45 tablespoons butter over medium heat and stir in flour. Cook for 1 minute, stirring constantly to make a Roux. Add water in 1/2 cup increments, stirring between each addition to be sure no lumps form. Add beef base and chicken base and bring mixture to a slow boil. Reduce heat and simmer 15 minutes. Soup will thicken. Stir in milk, half and half and reserved mushrooms and celery, with their cooking liquid. Season to taste with salt and pepper.