HEAT oil in skillet on medium-high heat. Add onion and mushrooms; cook 5 min. or until tender. Add cream cheese spread; cook and stir 3 min. or until melted and well blended. Remove from heat; cool. Stir in chives.

PREHEAT oven to 375°F. Roll puff pastry sheet on lightly floured surface to 25cmx35cm rectangle. Cut in half lengthwise to form 2 rectangles. Spread cream cheese mixture over rectangles, leaving 1-inch lengthwise border on sides.

ROLL in both long sides of each rectangle so they meet in centre. Brush with egg; fold in half. Press lightly; cover. Freeze 30 min.

CUT rolls into 1/4-inch slices. Place, cut-side up, on lightly greased baking sheets. Bake 15 min. or until browned.