DOUGH:

3 cups all-purpose flour
1-1/2 teaspoons salt
1 egg
3/4 cup water, approx.
4 teaspoons vegetable oil

In bowl, combine flour with salt. Beat together egg, water and oil; stir into flour mixture to make soft but not sticky dough that holds together in a ball. If necessary, add 1 tbsp. more water at a time, being careful not to make dough sticky. Turn out dough onto lightly floured surface; knead about 10 times or till smooth. Halve dough, cover with plastic wrap or damp cloth. Let rest for 20 minutes.

FILLING:

1 tablespoon butter
1/3 cup onion, finely chopped
1 cup potatoes, cold mashed
3/4 cup cheddar cheese, shredded
1/2 teaspoon salt
1/4 teaspoon pepper

Meanwhile in skillet, heat butter over medium heat, cook onion for 3 to 5 minutes or till tender. Transfer to a bowl, add mix in potatoes, cheese, salt and pepper. Working with one portion of the dough at a time, and keeping the remaining dough covered, roll out on a lightly floured surface to 1/16" thickness. Using 3 inch round cutter, cut dough into rounds. Place 1 tsp. filling on each round. Lightly moisten edge of one half of dough with water, pinch edges together to seal and crimp attractively. Place on cloth; cover with damp cloth to prevent drying out. Repeat with remaining portion of dough. In large pot of boiling salted water, cook perogies in batches, for 1-1/2 to 2 minutes or till they float to top, stirring gently to prevent perogies from sticking.

Variations:

Cottage Cheese: Combine 1 cup press cottage cheese, 1 beaten egg, 1/2 tsp. salt, 1/4 tsp. pepper and 1 tbsp. chopped green onion.

Mushroom: In skillet, melt 2 tbsp. butter over medium heat, cook 3 cups chopped mushrooms and 1/3 cup finely chopped onion for 7 to 9 minutes or until moisture has evaporated. Remove.