Artichoke, Mushroom, and Spinach Casserole Recipe

Preheat oven to 350 degrees F. Reserve a few mushrooms and set aside. Slice the remaining mushrooms and saute in 4 tablespoons of butter; set aside. In a saucepan, melt the remaining 2 tablespoons butter; stir in flour and blend. Add milk and stir well. Cook until thickened, stirring constantly. Add sauteed mushrooms, spinach, garlic powder or garlic, and salt; mix thoroughly. Arrange artichoke bottoms in the bottom of a rectangular baking dish. Spoon spinach mixture on top. In a small mixing bowl, combine sour cream, mayonnaise and lemon juice. Spoon sour cream mixture over spinach mixture. Arrange reserved mushrooms (sliced or whole) on top. Bake 25 to 30 minutes.