Bring a pan of salted water to the boil and simmer the brussels sprouts for 3-6 mins until tender. Drain and set aside.

Toast the hazelnuts in the same pan if you like. Once lightly golden and toasted, remove and set aside. Add the oil to the pan and fry the shallot with a pinch of salt over a medium-low heat for 6-8 mins until softened. Stir in the clementine zest and butter and, once the butter has melted, stir in three quarters of the juice. Bring to a simmer and cook for 1 min, then stir in the sprouts along with a good pinch of salt and pepper, then toss well.

Stir in most of the hazelnuts, tip into a serving bowl and sprinkle with the rest. Drizzle over the remaining clementine juice.