- Step 1
Preheat oven to 220°C. Heat half the oil in a large frying pan over high heat. Add half the chicken. Cook, turning occasionally, for 3 mins or until browned all over. Transfer to a plate. Repeat with the remaining chicken.
- Step 2
Add the leek, celery and garlic to the pan. Cook, stirring, for 5 mins or until leek softens. Return the chicken to the pan. Sprinkle the flour over the chicken mixture. Cook, stirring, for 2 mins or until flour is combined. Add the stock. Cook, stirring, for 2 mins or until sauce boils and thickens. Remove from heat. Add the cream and stir to combine. Add the asparagus, corn kernels, mustard and chives and stir to combine. Season with salt and pepper.
- Step 3
Spoon the chicken mixture into an 8-cup (2L) capacity ovenproof dish. Place the pastry over the filling. Use a sharp knife to trim edges. Press down pastry edge with a fork. Lightly brush with the egg. Place on a baking tray. Bake for 30 mins or until golden.