Peel the celeriac and cut into small cubes. Peel and dice the shallots. Heat a saucepan over a medium heat and add the butter. When melted add the shallots and cook for 2 minutes until soft and then add the diced celeriac and the bay leaf. Cover with the milk, bring to a simmer and cook until tender.
Drain the celeriac, but keep the milk. Puree the celeriac in a food processor whilst adding the milk a little at a time until you have a smooth consistency. Season with salt and pepper.
Trim away any excess fat and sinew from the duck breast. Score the skin, and season with Maldon salt and black pepper.
Place the duck breasts into a cold frying pan and cook over a high heat until the skin is golden. Drain off any fat as it melts and then sear the flesh side of the duck. Reduce the heat and cook for a further 3-5 minutes until the duck breast is firm to the touch but has some spring remaining. Add the honey to the pan and glaze the duck breast in the honey.
Allow the duck to rest for a few minutes before carving.
Bring a large pan of salted water and to the boil.
Remove any tough leaves from the sprouts, then cut a cross pattern into the bottom of each sprout. Cook in boiling water for 7 minutes or until tender, then drain and allow to cool slightly.
Cut the chestnuts into quarters.
Heat a large frying pan and add the remaining butter. Once melted add the chestnuts and sprouts, season with salt and pepper and toss in the butter for 2 minutes.
Place a spoonful of puree onto a plate, then add the sprouts. Top with some slices of duck and drizzle the remaining honey over and around the plate.
«For extra flavour try adding diced bacon to the sprouts as you fry them.»