Maybe not to everyone's liking, but if you are a fan of cooked marrow bones, they are easy to make at home. The rick, unctuous taste of warmed marrow spread on toast is both unique and delicious.
Start at your butcher by getting 3 or 4 pieces of marrow bone 1½-2" (3.5-5 cm) thick, cut crosswise as in the picture above, per person. Make sure that the marrow center is as big as possible.
You can sometimes also buy ones that are cut lengthwise, in which case you want two 4-6" (10-15 cm) halves per person. They should be have marrow end-to-end in a wide trough, without the bone end or growth plate included. Again, the key is to have a large ratio of marrow to the surrounding bone.
There are several ways in which the bones can be prepared, but they all start by removing any bits of meat or other tissue from the outer surface of the bone. This is easily done by scraping the bone with a paring knife held at right angles. Hold the bone in the other hand with a towel or knife-proof glove so as not to cut yourself.
My favorite way to prepare them is to simply season them lightly with salt and fresh-ground (white) pepper and roast them at 450°F (230°C) for about 15 minutes, until they are browned, but not bubbling. If the marrow is overheated, it will liquefy and ooze, kind of like cooking foie gras.
Other methods include poaching the bones in a gelatinous broth over very low heat for 15 - 20 minutes before roasting, or removing the marrow after soaking it for a half hour to loosen it, patting it dry, seasoning and breading it, and then shallow frying in oil. In the latter case, some recipes call for brining the marrow for up to two days in the refrigerator.
In any case, the marrow should be sprinkled lightly with Maldon salt and served with toasted bread on which it is spread.
Accompaniments can include garnishing herbs such as parsley or chervil, capers, or onion jam. For crosscut bones, provide a small, narrow spoon to scoop out the marrow.