Heat a little oil in a wok or non-stick frying pan. Add onion and potatoes and cook for 2-3 minutes. Add 300g chicken mince and cook for another 4-5 minutes.
Add curry powder and cook for one minute. Stir in chicken stock and bring to the boil. Reduce heat and simmer for 5 minutes or until most of the liquid has reduced.
Stir through cornflour and allow the mixture to thicken before adding mint. Remove from heat and set aside to cool completely.
Use a cookie cutter to cut approximately 22 discs from puff pastry, just thawed. When the chicken mixture is cold, spoon one heaped teaspoon onto one half of each disc. Fold the other side over to form a semi-circle and pinch the edges together to seal.
Add enough vegetable oil to a wok to reach a depth of 5cm. Heat over medium-high heat until a small piece of bread sizzles when dropped in. Add 5-6 curry puffs and cook for 3 minutes or until puffed and golden. Use a slotted spoon to transfer to a plate lined with paper towel. Repeat, in batches, with the remaining curry puffs. Serve immediately.
