COOK and stir bacon in medium skillet on medium heat 5 min.; drain. Add onions and garlic; cook and stir 4 min. or until bacon is crisp; drain. Stir in chiles; cool.
HEAT oven to 400°F. Roll out pastry on lightly floured surface to 11-inch square; cut into 12 smaller squares. Brush edges lightly with egg. Spoon about 1 Tbsp. bacon mixture onto center of each square; fold diagonally in half. Press gently on tops to remove excess air; seal edges with fork. Bend slightly to resemble half moons. Make small cut in top of each to vent steam. Place on parchment-covered baking sheet; brush with remaining egg.
BAKE 20 min. or until golden brown.