Finely chop mushrooms by hand, or alternatively, pulse in a food processor until finely chopped
Heat 1 tbs oil in a large saucepan over medium heat. Add onion, saute for 3 minutes or until softened. Add curry powder, cook, stirring for 1 minute. Add mushrooms, increase heat to high and cook for 5 minutes or until moisture has almost evaporated
Add mince, cook, breaking up mince with wooden spoon until mince changes colour. Sprinkle over flour, stir until well combined. Stir in stock and kumara, bring to the boil. Reduce heat to medium, simmer, uncovered for 8 minutes or until kumara is tender and mixture is thick. Set aside to cool. Stir in peas
Place an oven tray into the oven. Preheat tray and oven to 220°C. Lightly grease 6 x 8cm base measurement pie pans. Cut 1 x 20cm circle from each sheet shortcrust pastry. Use to line bases and sides of pans. Divide mince curry mixture between pie tins. Fold excess pastry over filling to partially cover. Brush pastry with water and season. Place curry pies onto hot tray. Bake for 20-25 minutes or until golden. Serve