Directions

1. In a medium bowl, mix together the mashed potatoes, 1 cup flour, eggs, salt and pepper until well blended. Spoon into a clean plastic bag.
2. Bring 5 quarts of water to a boil in a large pot. Adjust heat so that water boils very gently. Cut a small opening in the corner of the baggie, and squeeze out dumplings into the water, cutting with scissors at 1 inch intervals. Let the dumplings simmer uncovered until they float to the top. Remove with a slotted spoon, and place in a 2 quart baking dish. Keep warm.
3. Preheat the oven to 350 degrees F (175 degrees C). Melt butter in a skillet over medium heat. Saute onion in butter until tender. Blend in 2 tablespoons flour until smooth. Pour in cream and broth, and cook, stirring constantly until thickened. Remove from heat and stir in half of the Parmesan cheese and half of the Jarlsberg until smooth. Pour over the dumplings in the dish. Sprinkle remaining cheeses over the top.
4. Bake uncovered for 45 minutes in the preheated oven, until the top is golden brown and sauce is bubbly.