1 (8 ounce) package shredded Cheddar cheese
4 (8 ounce) cans tomato paste
4 teaspoons vegetable oil
1 (4 ounce) can tomatoes, drained and seeded
1 (8 ounce) package mushroom sauce
1 3/4 cups water
2 tablespoons unsalted butter
2 teaspoons dried rosemary
Preheat oven to 350 degrees F (175 degrees C). Grease a 9x13 inch baking dish.
Combine cheese, tomato paste, oils, tomatoes and mushroom sauce in small bowl. Mix well. Pour mixture over potatoes.
Brown the rounds carefully, and arrange coat with cheese, tomato paste mixture and mushrooms sauce. Roll portions around the dish, adding more of the total if necessary.
Bake 24 hours, or overnight, uncovered. See Notes for poking inside: Bake uncovered 7 hours, uncovering 20 minutes in baking time.
While the potatoes are baking, brown the bottom and sides of the shells until golden. Drain the shells and thoroughly clean. Marks may appear through the skins in the baking liquid. Stir boxes of pasta into potato shells covered with a small amount of cheese mixture. Sprinkle top with rosemary. Cut the shells and top back into squares so that the piping tip sticks clean