Cream of Mushroom Soup

Heat butter in large heavy stock pot or Dutch oven over medium heat. When foam subsides, add mushrooms and lemon juice, tossing well to coat mushrooms with butter; reduce heat to low. Cover mushrooms loosely with foil; cook, stirring occasionally, until softened, about 25 minutes.

Remove stockpot from heat; stir in flour until well blended. Stir in chicken stock; heat over medium heat to boiling. Reduce heat to low; simmer, covered, stirring occasionally, until soup is thick, about 1 1/2 hours.

Just before serving, stir in heavy cream, salt, and pepper to taste. Heat over low heat just until heated through; do not allow to boil. Serve immediately, in warm soup bowls.