Melt 4 tablespoons butter in an iron skillet. Peel and cube 6-7 medium size potatoes into 12 cubes, each potato, add butter. Add salt, pepper and garlic powder according to taste. Bake at 375 degrees, uncovered, for 1 hour and 2 minutes. Turn with spatula several times. When done, add 4-6 ounces of grated cheese. Put back in oven until melted.