Make these ahead of time for convenience and ease in serving. This recipe includes freezing instructions.

Perogies

Filling:
8 to 10 potatoes
1 onion, finely chopped
6 tablespoons butter 2 cups shredded cheddar cheese (8-ounces) 2 cups shredded mozzarella cheese (8-ounces) 4 to 6 strips bacon, cooked and crumbled (optional) Salt and pepper to taste

Dough:
2 1/4 cups reserved potato water, cooled to lukewarm 2 large eggs 6 tablespoons vegetable oil 6 to 7 cups all-purpose flour 1 1/2 teaspoons salt

For Filling: Peel and cut potatoes into cubes. Boil until tender. Reserve cooking water for dough.
Meanwhile, saute onion in a butter; set aside to cool to lukewarm.
Mash potatoes and place in medium-sized bowl. Add onion with the butter, cheeses and bacon; season to taste with salt and pepper and mix well. Set aside.
For Dough: Combine potato water, eggs and oil; mix well.
Combine flour and salt in a large bowl, make a well in the center. Pour water/egg mixture into well and stir until mixture is smooth.
Turn dough out onto a lightly floured surface and knead several times.
Place dough in well-greased bowl, turning dough once and cover. Let rest for at least 20 minutes to 2 hours.
On a lightly floured surface, roll dough out to about 1/8-inch thickness. Cut dough into circles with a large biscuit cutter or coffee mug. Fill with about 1 teaspoon of potato mixture. Pinch edges together so the seam is secure.
Place on baking sheets lined with waxed paper and freeze. Once frozen, place in a large zipper-style plastic bag to store.
To Cook Perogies: Bring a large cooking pot of water to boil. Remove perogies from freezer once the water has come to a full rolling boil.
Cook perogies in batches of 6 to 8 in boiling water. They are done when they rise to the water's surface. Drain well and place in a serving bowl. Drizzle with melted butter and sprinkle with chopped chives, if desired, and serve. Perogies also go well with sauteed onions and sour cream.

Makes about 8 dozen.

Note: Perogies can be fried or deep-fried.