Meanwhile, heat the olive oil in a large frying pan set over a medium heat. Add the turkey and onion and cook for 2 to 3 minutes, until the onion has softened and the turkey has warmed through. Stir in the curry paste and cook for 1 minute, then add the tomatoes and coconut milk and mix well. Simmer for 5 minutes. Just before serving, add the cooked potatoes to warm through in the curry.