Line cookie sheet with cooking parchment paper. Remove pie crust from pouch; unroll on lightly floured surface. Roll to 14-inch round. Transfer to cookie sheet. Spread three-fourths of the caramelized onions over crust, leaving 4-inch border around edge. In medium bowl, toss pears with flour. Arrange pears over onions; top with remaining onions, the pecans, cheese and thyme. Fold 4-inch borders of dough over filling, pressing gently to seal. Brush dough with beaten egg.