Frying lengths of black pudding, as some recipes suggest, is not an efficient procedure. The casing shrinks, and the pudding bulges out like a paunch over a belt. Slicing the pudding works better. You can fry or grill the disks, or -- much easier -- bake them on a lightly oiled baking sheet. I give them 15 minutes at gas mark 5/180C.
Creamy things, such as gratin dauphinois, and acidic things, such as stewed apple, go particularly well with it. But last night we had it with small (about 1.5cm cubes) roast potatoes, and kale. I steamed the kale for about eight minutes, and stirred it into a bechamel seasoned with pepper and nutmeg.
My general rule with bechamel is to cook as much as will be thickened by a dstsp of flour for each person. There is a recipe for bechamel in this entry on macaroni cheese; but this time, I flavoured the milk first. I peeled an onion, halved it, covered it with milk in a small saucepan, and added a bay leaf, some grated nutmeg, and a little salt. I brought the contents of the pan slowly to a simmer, turned off the heat, covered the pan, and left it for 30 minutes. I strained the milk into a jug, and carried on in the normal way.