In a large frying pan , heat 2 tablespoons butter and 1 tablespoon olive oil. Fry the potatoes, one layer at a time, until tender and golden brown on both sides. Add more butter and oil as needed. Drain on paper towels.
Arrange the potatoes in two or three layers in a large, shallow baking dish and sprinkle each layer with salt and pepper.
Combine the cream sauce with the tomato puree and the drained tomatoes, and spoon over the top layer of potatoes. Sprinkle with bread crumbs, then with cheese. Dot with butter. Bake in a preheated 400 degree oven for 25 minutes or until the top is golden brown.
CREAM SAUCE-In a saucepan over medium heat, melt the butter. Stir in the flour and cook , stirring into a smooth paste. Gradually add the milk and cook, stirring, until the sauce thickens. Add the cream, salt, pepper and nutmeg, and cook into a medium-thick sauce.