Lovely bones; marrow and parsley salad.

One of the signature dishes of Madrid is cocido. It´s one of those balls-to-the-wall porcine fests, chock full of every conceivable bit of it, and complemented with chick peas, potatoes, cabbage, and tomato sauce for good measure.
Everyone has their favourite bit. Some prefer the chorizo, others the morcilla. The cabbage is usually given a wide berth, and the boiler chicken considered a little dull, but everybody loves the broth, infused with all the flavour that can possibly go into soup, and of course the garbanzos are always a hit. In our house, the ugly fight breaks out over the marrow bone.
There are many bits of everything else, but only one marrow bone, two at most, and my mother (and her mother before her) always collars it, so that I was quite old when I tried the delights of marrow for myself, and then away from home. And when I did, I loved it, but wondered if I´d have to be a proper motherly matron before being allowed to stake out the marrow in every cocido.
It turns out that no, it´s ok, non-matriachs. Marrow can be roasted and eaten just like that, without all the cocido complications.
Though it´s not that easy to get many marrow bones, it can be done. Butchers in Spain give them away, and tend to hoard them and give just one each to each cocido maker. It works out pretty well for them, as they sell chorizo, morcilla, tocino (lard), shin of beef and maybe even the boiler chicken too, and then look courtly and generous, in a Sweeney Toddish way, by giving away one single bone.
But if you go at the beginning of the week, at a quiet time far from the weekend cocido madness, you might be lucky and wheedle four or five good pieces from the middle of the bone.

The thing to do then is, of course, call your mother and offer to serve up a mini troglodite fat-fest.
All you need is to fire up the oven, wait for it to be hot, put the bones in a dish and wait til they´re cooked. I´ve read that the minute the fat starts running out you should stop, but I´ve always found bloody bits inside the bone, which is gross. Leave them there half an hour at least, and wait til it´s all white.
During that half hour, take a bunch of parsley and pick out the leaves. Chop them roughly, and put them in a bowl with some thinly sliced fresh red onion and a handful of capers. Dress with fruity olive oil and lemon, no salt. Toast bread, a ciabatta-ish one for preference.

Serve the bones with the toast, the salad and a little bowl of Maldon salt. Proceed to scoop out the jellified, quivery fatty inside, spread it on the toast, sprinkle with salt and top with the salad.

It´s a wonderful starter, and practically free, given that both the bones and the parsely will have cost exactly nothing.
And on the plus side, you get to give the picked out bones to your dogs, who will be very happy indeed. A win-win dish for lean January when everybody´s skint.