Put the gnocchi in a deep ovenproof frying pan and cover with boiling water and a pinch of salt. Simmer for 2-3 mins, then drain and leave to steam-dry.

Combine a splash of the milk with the cornflour until you have a smooth paste, then add to the rest of the milk. Pour the mixture into the frying pan, then add the fish pie mix and spring onions, and bring to a gentle simmer. Cook, stirring frequently, until the sauce has thickened and the fish is just cooked, about 4-5 mins. Season well. Stir in the herbs, crème fraîche, capers and peas, and bring back to a simmer.

Heat the grill to medium-high. Arrange the gnocchi over the filling, then brush with the oil and season with some black pepper. Grill for 5-10 mins, or until the gnocchi has puffed up and is starting to turn golden on top. Serve with the broccoli or green beans on the side.