Melt 1 Tbsp. butter in large skillet on medium-high heat. Add mushrooms; cook 6 min. or until tender, stirring frequently.
Meanwhile, melt 2 Tbsp. of the remaining butter in medium saucepan on medium heat. Whisk in flour; cook and stir 1 min. Gradually whisk in milk, then sour cream; cook 4 min. or until thickened, stirring constantly. Stir in shredded cheese and pepper; cook 1 min. or until cheese is melted.
Grease 3-qt. casserole with remaining butter. Layer 1/3 each of the potatoes and mushrooms in casserole; repeat layers twice. Cover with cheese sauce. Sprinkle with Parmesan; cover.
Bake 1-1/2 hours or until potatoes are tender and top is golden brown, uncovering after 1 hour. Let stand 10 min. before serving.
This sensational side dish pairs well with cooked lean meat or poultry.
Prepare using KRAFT Shredded Mozzarella Cheese.
Calories From Fat
% Daily Value*
Total Fat 8g
Saturated Fat 5g
Trans Fat 0g
Total Carbohydrates 16g
Dietary Fiber 1g
* Percent Daily Values are based on a 2,000 calorie diet.
16 servings, 1/2 cup each
* Nutrition information is estimated based on the ingredients and cooking instructions as described in each recipe and is intended to be used for informational purposes only. Please note that nutrition details may vary based on methods of preparation, origin and freshness of ingredients used.