Choose a new cookbook worth up to £28 when you subscribe to our magazine.
Heat oven to 200C/180C fan/gas 6. Heat the butter in a large ovenproof dish over a medium heat. Cook the leek for 4-5 mins, stirring regularly, until just tender. Add the rice and stir for a further 2 mins.
Add the stock and milk, bring to the boil and bubble for 5 mins before sitting the haddock on top. Cover with a lid or foil and bake in the oven for 18 mins until the rice is tender.
Fold in the crème fraîche and spinach, season with plenty of black pepper, then cover the pan again and leave to rest out of the oven for 3 mins before serving – the steam will soften the spinach.