300g potatoes, peeled and cut into large chunks
250g sweet potatoes, peeled and cut into large chunks
450g skinless salmon fillets
450ml skimmed milk
25g butter, melted
2 leeks, trimmed and sliced into chunks
1 clove garlic, crushed
1 tbsp plain flour
100g peas, defrosted
½ x 25g pack tarragon, roughly chopped
- Heat the oven to 190°C/170°C fan/gas 5. Cook the potatoes and sweet potatoes in boiling salted water for 5 minutes. Drain well and set aside until they are cool enough to handle.
- Meanwhile, put the salmon in a saucepan with the milk and bring to a simmer. Cook gently for 4-5 minutes, until the fish is opaque and cooked through. Remove the fish and set aside, reserving the milk.
- Grate the potatoes and sweet potatoes into a bowl. Pour half the melted butter over the potatoes and mix well. Season with pepper and set aside.
- Pour the remaining butter into a clean pan, add the leeks and garlic and cook for 3-4 minutes, until softened. Stir in the flour, then gradually whisk in the reserved milk to make a smooth sauce. Cook over a gentle heat, stirring continuously, until simmering. Cook for 2 minutes, then remove from the heat
and season. Stir in the peas and chopped tarragon.
- Flake the salmon and gently fold into the sauce. Spoon the mixture into a deep 1.5-litre ovenproof dish and top with the potato mixture. Bake for 20 minutes, until golden. Serve with green beans.