Fish Pie with Rosti Filling Recipe by Rosie Sykes

Fish pie is one of the family's favourites: this takes out a lot of the work, like making a white sauce and mashed potatoes of land.

Makes 4firm white fish fillets 500gleek 1, thinly sliced, using as much of the green part as possiblehot milk 300mlcream cheese with herbs and garlic 100g baby spinach 100g parsley a small handful of chopped tarragon a few sprigs, leaves chopped smoked mackerel (optional) 80g, crumbled pot prawns 1 jar (about 55g) grated lemon zest and juice from ½ large potatoes red earth 700g, peeled capers 2 tbspbutter 60g, melted sea salt and black pepper and milk in a small roasting pan, season well and cover with foil. Bake for 15 minutes until the fish is cooked through and the leek has softened.

Pass the milk through a food processor and add the cream cheese , spinach and herbs. Whisk to obtain a smooth and thick sauce.

Separate the fish from the leeks, remove the skin if there is any and crumble the fish. Mix the poached fish, mackerel and leeks. Break up the potted shrimp as best you can and add that too. Add the lemon juice and zest and stir in the herb sauce. Taste and adjust the seasoning. Spread this mixture evenly in the roasting pan.

Coarsely grate the potatoes and toss with the capers, melted butter and plenty of seasoning. Spread the potato mixture evenly over the fish.

Bake for 35 minutes until the topping is golden brown and crispy on top and soft on the bottom. Test by piercing the potato filling with a sharp knife: it should slide easily. Let stand 5 minutes before serving. I like to eat fish pies with peas.

From Roasting Pan Suppers by Rosie Sykes and National Trust Books (HarperCollins, £14.99)< /em>