Potato Pierogi with Sour Cream-Chive Sauce

MIX flour and 1 tsp. salt in large bowl. Cube half of the cream cheese; cut into flour mixture with pastry blender or 2 knives until mixture resembles coarse crumbs. Add egg and water; mix until mixture forms ball. Place on lightly floured surface. Knead 5 min. or until smooth and pliable. Wrap in plastic wrap; set aside.

MIX remaining cream cheese, potatoes, onions, remaining salt and pepper. Roll out dough to 1/8-inch thickness. Cut into 48 (3-1/2-inch) rounds, rerolling trimmings as necessary. Spoon 1 Tbsp. potato mixture onto center of each round. Brush water halfway around edge of each dough round; fold in half to enclose filling. Seal edges with fork.

BRING large saucepan of water to boil. Add pierogi, 12 at a time; cook 3 to 4 min. or until they float to surface. Remove with slotted spoon; drain.

MELT 1 Tbsp. butter in large skillet. Add 1/4 of the shallots and 12 pierogi; cook and stir 4 min. or until pierogi are golden brown. Repeat, in batches, with remaining butter, shallots and pierogi. Mix sour cream and chives. Serve with pierogi.