Sauté garlic in 1 teaspoon butter in a medium saucepan. Add wine, sour cream, cream cheese and chopped mushrooms, and cook over low heat until mixture is smooth.

Meanwhile, make a roux in a separate saucepan by melting 4 tablespoons butter and stirring in the flour until smooth. Cook over low heat, stirring constantly, for about 10 minutes. Add roux to cheese mixture. Add salt and pepper to taste and 1 teaspoon lemon juice. Allow mixture to cool.