Step 1

Heat the oven to 200°C/180°C fan/gas Put 2 tbsp oil in a medium shallow roasting tin and put in the oven to heat up. Add the potatoes and onions to the tin, then roast for 30 minutes or until golden, turning occasionally.

Step 2

Meanwhile, heat another 1 tbsp oil in a large saucepan and brown the mince over a medium heat, then add the chopped tomatoes and 150ml cold water. Bring up to the boil, then reduce to a simmer. Stir in the harissa, season, then simmer gently for 20 minutes.

Step 3

Heat the grill to medium, spoon the beef mixture over the potatoes, sprinkle over the feta, then grill for 5 minutes. Sprinkle with the fresh herbs to serve