Plump Perogies

Dough: In bowl, combine flour + salt. Beat together egg, water + oil; stir into flour mixture to make soft but not sticky dough that holds together in ball. If necessary, add 1 tbsp water at a time, being careful not to make dough sticky. Turn out dough onto lightly floured surface; knead about 10 times or just until smooth. Halve dough; cover with plastic wrap or damp cloth. Let rest for 20 mins. Filling: Meanwhile, in skillet, heat butter over medium heat; cook onion for 3 - 5 minutes or until tender. Transfer to bowl and mix in potatoes, cheese, salt and pepper. Working with one portion of dough at a time and keeping remaining dough covered, roll out on lightly floured surface to about 1/16-inch (1.5 mm) thickness. Using 3-inch (8 cm) round cutter, cut dough into rounds. Place 1 tsp (5 mL) 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 1.5 - 2 minutes or until they float to top, stirring gently to prevent perogies from sticking together or to bottom of pot. With slotted spoon, remove to colander to drain. In large heavy skillet, melt butter over medium heat; cook onion for about 5 minutes or until golden. Add perogies and toss to coat and warm through. Serve with sour cream. Filling Variations: Cottage Cheese: Combine 1 cup (250 mL) pressed cottage cheese, 1 beaten egg, 1/2 tsp (2 mL) salt, 1/4 tsp (1 mL) pepper and 1 tbsp (15 mL) chopped green onion. Freeze uncooked perogies on baking sheets, then pack them in freezer bags and freeze for up to 1 month. Do not thaw them before cooking.