Smoked haddock & wild mushroom traybake

Heat oven to 180C/160C fan/gas 4. Put the potatoes in a large pan and cover with the chicken stock and 50ml water. Bring to the boil, then gently simmer for 8-10 mins until tender. Carefully remove with a slotted spoon and set aside, reserving the stock.

Heat the oil in a frying pan and cook the onions for about 8 mins until golden brown. Spread them over a 26 x 5cm ovenproof dish and arrange the potatoes neatly on top. Season well and pour over the chicken stock. The stock should soak into the onions, leaving the potatoes dry.

Spoon the crème fraîche over the potatoes in an even layer. Lay the haddock on top, then scatter over the mushrooms and butter, leaving some of the potatoes and onions visible. Cover with foil and put in the oven for 8 mins.

Meanwhile, make the topping by mixing the lemon thyme, brioche breadcrumbs and Parmesan. Remove the foil from the fish and sprinkle over the crumb topping (making sure that some of the mushrooms are still visible). Return to the oven for 5 mins, then place under the grill for about 2 mins or until golden brown.

To give the dish some acidity, lay the lemon segments in a roasting tin and char with a blowtorch, or char in a griddle pan over a high heat. Arrange on top of the golden crust and serve in the middle of the table with wilted spinach, if you like.