800g potatoes, peeled and sliced into 2cm-thick slices
A small bunch of spring onions, trimmed and sliced
2 bunches of watercress, washed and large stalks removed
A splash of flavourless oil
150g crème fraiche
200ml skimmed milk
250g smoked trout, (kahawai) skinned, boned and flaked
A squeeze of lemon
Salt and black pepper
Preheat the oven to 180C. Put the potatoes in a large pan of salted water, and simmer for 5-7 minutes.
In a lidded pan large enough to take the watercress, add a generous splash of oil and heat over a medium to high heat. Add the watercress and toss until it starts to wilt. Put the lid on for aﾠminute, so that the stalks soften.
Remove the lid and pour in the milk, bring to a simmer and add the crème fraiche, then pour the whole lot into aﾠfood processor and whizz to a green-flecked sauce.
When the potatoes are ready, drain and refresh under cold water so they don’t cook any more. Toss the sauce and potatoes together, season to taste and spoon half of them into a baking dish that will fit them all snugly.
Mix together the smoked kahawai, spring onions and lemon.
Flatten out the potatoes and cover with the smoked fish mixture. Cover with the rest of the potatoes, pouring over any remaining watercress sauce.
Place in the oven and bake for about 25-30 minutes until the potatoes are completely cooked.