Heat oil in a pan and saute chicken for 2-3 minutes or until golden. Just brown the ingredients to seal off the flavours but don't cook completely - this is done in the oven. Add garlic, spring onions, corn and capsicum and cook for 2 minutes or until vegetables have heated through. Reduce heat and stir through the asparagus, then stir through remaining ingredients to coat well. Stir the sauce through the sauteed chicken and vegetables and allow to cool. Never add hot filling to raw pastry.
Melt the butter over a medium heat and add the flour, stirring constantly. Gradually pour in the chicken stock stirring to avoid lumps. Continue stirring until a thickish sauce consistency is achieved.
You can buy ready-made pastry for the base, but Geoff says it won't taste as good as his pastry below
Sift the flour, baking powder and salt into a large bowl. Add the butter and rub through the flour until a breadcrumb appearance is reached. Add the cold water gradually and incorporate until a soft dough consistency is formed. Turn out and knead on a floured surface until smooth.
Line a 22cm pie dish with half the prepared pastry. Trim the pastry around the edges of the tin. Add the pie filling, push down well and cover with remaining pastry (or you may prefer to use puff pastry for the top). Tuck edges into the side of pie tin to neatly seal the top. Brush with beaten egg, sprinkle with cornmeal and make 2-3 small cuts in top of pastry to allow steam to escape.
Bake in preheated 190C oven for 30 minutes, or until pastry is cooked through and filling is hot. Serves 6.