Step 1

Preheat oven to 200C/180C fan-forced. Heat oil in a saucepan over medium heat. Add garlic and chicken. Cook, stirring, for 5 minutes or until browned. Add zucchini, carrot and potato. Cook for 3 minutes. Add 1 cup stock to pan.

Step 2

Place cornflour and 1/4 cup remaining stock in a bowl. Stir to form a paste. Stir in remaining stock. Stir cornflour mixture into chicken mixture. Bring to the boil. Reduce heat to medium-low. Simmer for 5 minutes or until just thickened. Stir through parsley and tarragon. Spoon mixture into a 5 cup-capacity ovenproof dish.

Step 3

Make pastry: Sift rice flour, cornflour, buckwheat flour and salt into a large bowl. Add spread, 1 tablespoon cold water and sunflower oil. Using a flat-bladed knife, stir to form a dough, adding extra cold water if needed. Knead dough for 3 minutes or until smooth and combined. Shape dough into a disc.

Step 4

Roll pastry out on a lightly floured surface until large enough to cover dish. Place pastry over filling. Pinch edges to seal. Brush with egg. Bake for 35 to 40 minutes or until pastry is golden. Stand for 5 minutes to cool. Serve.