1.Heat oil in a large frying pan over medium-high heat; cook onion, stirring, for 4 minutes or until onion softens. Add beef; cook, stirring, until beef changes colour. Add paste, sauce, and blended gravy powder and the water; bring to the boil, stirring. Reduce heat; simmer, uncovered, for 10 minutes or until thickened slightly; cool.
2.Preheat oven to 200°C (400°F). Oil two 12-hole (2-tablespoons/40ml) deep flat-based patty pans.
3.Cut 24 x 7cm (2¾-inch) rounds from shortcrust pastry; press into pan holes. Divide beef mixture among pastry cases. Brush edges with a little of the egg.
4.Cut 24 x 6cm (2½-inch) rounds from puff pastry; top pies with puff pastry lids. Press edges firmly to seal; brush lids with remaining egg. Sprinkle with sesame seeds, cut a small slit in the lid of each pie.
5.Bake for 20 minutes or until browned lightly. Stand pies in pan 5 minutes before serving.