Sago
I parboil sprouts and chill in the fridge, on the day I pan fry them with pancetta and chestnuts.
I do the same as Sago, I gave in the last time we had family and bought a packet of freshly prepared sprouts. I fry pancetta with thinly sliced savoy cabbage as well.
At Christmas, I precook sprouts and then fry them with the pancetta and a packet of Merchant Gourmet chestnuts. I also parboil the potatoes on Christmas Eve when I'm boiling the Giblets for gravy. I recently saw a recipe where they roasted the potatoes on Christmas Eve and finished them off in Goose Fat on the day. I actually micro-waved the sprouts and potatoes the day before when DH worked, DH likes to do them from scratch.