Wash the sprouts and trim off the stalky bottoms so they’re neat and flat. Pull off any torn outer leaves. Halve the sprouts.
Finely grate the zest from the clementines and juice them. Dice the butter.
Add the butter to a deep frying pan or wok. Set over a medium-low heat and warm for 2-3 mins till the butter melts and turns a deep, nutty brown colour. Keep the heat medium-low and don’t overcook it – you want the butter to be a rich, caramel brown. When it’s turned and become nutty, stir in the clementine zest and juice.
Add the sprouts with a little pinch of salt. Stir and fry for 4-5 mins so the sprouts are just tender, and are coated in the butter. Tip into a serving dish, grate over a little nutmeg and serve.