Preparation Melt butter in heavy large skillet over medium heat. Add leeks; stir 1 minute. Reduce heat to low; cover and cook until leeks begin to brown, stirring occasionally, about 7 minutes. Stir in pear and sugar. Increase heat to medium; saut
 uncovered until any liquid evaporates, about 2 minutes. Season with salt and pepper. Transfer to bowl; cool. Stir in cheese and chives. Place puff pastry sheets on work surface. Using 4 1/2-inch-diameter tartlet-pan rim or bowl as aid, cut out 4 rounds from each pastry sheet. Roll out each pastry round to 5-inch circle. Place leek mixture on half of each pastry round, dividing equally. Brush pastry edges with egg glaze. Fold pastry over filling, pressing to adhere. Press edges with fork to seal. Brush turnovers with egg glaze. Pierce pastry in several places with toothpick. Place on baking sheet. Chill 20 minutes. Preheat oven to 400°F. Bake turnovers until puffed and golden, about 18 minutes. Serve warm.
Preparation Melt butter in heavy large skillet over medium heat. Add leeks; stir 1 minute. Reduce heat to low; cover and cook until leeks begin to brown, stirring occasionally, about 7 minutes. Stir in pear and sugar. Increase heat to medium; saut
 uncovered until any liquid evaporates, about 2 minutes. Season with salt and pepper. Transfer to bowl; cool. Stir in cheese and chives. Place puff pastry sheets on work surface. Using 4 1/2-inch-diameter tartlet-pan rim or bowl as aid, cut out 4 rounds from each pastry sheet. Roll out each pastry round to 5-inch circle. Place leek mixture on half of each pastry round, dividing equally. Brush pastry edges with egg glaze. Fold pastry over filling, pressing to adhere. Press edges with fork to seal. Brush turnovers with egg glaze. Pierce pastry in several places with toothpick. Place on baking sheet. Chill 20 minutes. Preheat oven to 400°F. Bake turnovers until puffed and golden, about 18 minutes. Serve warm.