Let me say, right at the start, that the Potato & Onion Filling gives these the name of "knishes." Fill them with mushrooms and they become Piroshkis. These little knishes have to be one of the best-tasting hors d'oeuvres. They are also a great accompaniment to soup or salad. I recently prepared these for a Super Bowl game and everybody loved them. Traditionally made with a heavy-duty dough, making these with puff pastry truly elevates them to gastronomical heights. I have further simplified preparation using the potato flakes. The abundance of onions is most predominant in taste, so potato flakes can be used.

Onion Potato Filling:
3 large onions, chopped
3 tablespoons margarine

3 cups instant mashed potato flakes
3 cups boiling water
3 tablespoons margarine
salt and freshly ground pepper to taste

Sauté onions in margarine about 20 minutes, or until onions are lightly browned. (Careful not to burn or onions will be bitter.) Meanwhile, add the boiling water to the potato flakes, stir in the margarine and salt with a good amount of pepper. Stir in the browned onions. Allow mixture to cool.

Puff Pastry:
1 package (17 ounces) Pepperidge Farms Puff Pastry (2 sheets)
1 egg, beaten
12 tablespoons grated Parmesan cheese

Cut pastry sheets in thirds on the fold. Cut each third in half crosswise. You will have 12 pieces. On a floured pastry cloth, roll out each piece to measure 4x8-inches. Place a few tablespoons Potato Onion Filling along the 8-inch side, fold dough over and press edges down with the tines of a fork. Scallop the edges.

Place knishes on a greased cookie sheet, brush tops with beaten egg and sprinkle with cheese. Pierce tops in 4 or 5 places with the tines of a fork. Bake at 400° for 25 to 30 minutes, or until tops are nicely browned. Remove from pan and allow to cool on brown paper.

To reheat, place knishes on a cookie sheet, cut each into 4 pieces and heat in a 350° oven for 15 minutes, or until heated through. Yields 48 knishes.