Duck has lots of classic fruity partners but rhubarb often isn't one of them. I'm not sure why – for me, it's a perfect marriage.
You can use a whole duck for this, or duck breasts, which are readily available in butchers and supermarkets.
4 duck breasts weighing about 160-200g each
Salt and freshly ground black pepper
2tbsp cider vinegar
2tbsp granulated sugar
A couple of good knobs of butter
Cut the rhubarb into batons, roughly 6-7cm x ½cm wide. Season the duck breasts, heat a heavy frying pan and cook the breast with the skin down for about 5 minutes on a medium heat, pouring off any fat as it's cooking, which you can save for roast potatoes. Turn the breasts over and cook for another 4-5 minutes, keeping them nice and pink.
Meanwhile, heat the vinegar in a wide pan with the sugar and a tablespoon of water and stir until the sugar has dissolved.
Add the rhubarb and butter and simmer for 30 seconds with a lid on, then remove the rhubarb with a slotted spoon and transfer to a plate.
Continue simmering the liquid until you have just a couple of tablespoons; then mix with the rhubarb and remove from the heat.
To serve, cut the duck breasts into 7 orf 8 slices, vertically, and arrange on warmed serving plates. Spoon the rhubarb and syrup on top.