Heat oven to 350° F.

Place potatoes in large pot of salted water and bring to boil. Reduce heat to medium-low, cover and simmer until tender. Drain and transfer potatoes to flat bottom bowl and mash. Add cheese, milk, sour cream, butter, salt and pepper. Mash all ingredients with potatoes until smooth. Pour mixture into baking pan and cover with foil. Bake, 30 minutes, covered. Uncover potatoes during last 10 minutes to allow browning.