Marrow always needs a little help in terms of adding flavour – and some chopped-up cooking chorizo and breadcrumbs really do the trick. If you can't buy cooking chorizo, you can get away with slicing chorizo, but use a bit less as it will be saltier.
1 small marrow
2tbsp vegetable or corn oil
Salt and freshly ground black pepper
A couple of good knobs of butter
1 medium onion, peeled, halved and finely chopped
120g cooking chorizo
120g fresh white breadcrumbs
Top and tail the marrow if necessary, then cut into four lengthways and scoop out the seeds. Cut in to 1cm-thick slices, then lay on a tray and scatter with a little salt and leave for 20 minutes. Meanwhile, heat the butter in a pan and gently cook the onion and chorizo for 4-5 minutes, breaking it up with the back of the spoon as it's cooking, until it resembles mincemeat. Remove from the heat then stir in the breadcrumbs. If the chorizo hasn't broken down, you can give it a quick blend with the breadcrumbs in a food processor.
Preheat a grill to the maximum setting. Drain any liquid from the marrow slices and pat dry with kitchen paper; then heat the oil in a large, heavy, reliable or non-stick frying pan. Season the marrow with pepper only; then fry on a fairly high heat for 4-5 minutes, turning the pieces as they are cooking, until they are tender. You will probably need to do this in a couple of batches, depending on the size of your pan.
Once cooked, toss the marrow in two-thirds of the breadcrumb mixture and transfer to an ovenproof dish; scatter the rest of the crumbs on top. Place the dish under the grill for a few minutes until nicely coloured.