A few thoughts on the slow cooking, what with winter drawing in, and that, of the off cuts such shanks, beef short rib, ox tail and the like. Also lamb necks. They're completely delicious.
Take the meat out of the fridge and place on a rack to warm and to dry out the surface a little. Heat a nice, thick bottomed pan. Using a small sharp knife, score any large areas of surface fat. Add a little veg oil to the pan (you can always add more) and sear the outside of the meat, taking care to brown the meat all over and render as much of the fat as possible. (Browning the meat will create a set of flavour compounds you don't otherwise create).
Remove the meat, tip any remaining fat and lower the heat to medium. You can wipe the pan with a little kitchen paper to remove all the oil, particularly if it has burned a little, but don't rub the glaze from the pan. Add a carrot, halved and chopped lengthways, and an onion and a leek, cut into similar sized pieces. Stir these around the pan to deglaze and allow to soften a little. Add some roughly chopped garlic, cook for another minute and add two tomatoes (skinned and ideally deseeded, though you might not bother). Cook until they fall apart, add a glass of wine (white is fine with lamb) and 1/4 of a glass of vinegar. The jelly that surrounds the seeds in a tomato contains the highest concentrations of glutamate, so it's good to keep these for beef dishes. If you're feeling like refining things you can put the seeds in a sieve and strain the liquid through.
Reduce everything by at least half, ideally by 4 or 5. The alcohol will stick around for longer than you might think.
Add enough stock or water to the pan to cover the meat and return the meat to the pan, as well as a few bay leaves and any herb stalks you may have . Bring to a very gentle simmer, cover and cook until the meat comes away from the bone or can be mashed with a fork, probably upwards of an hour and a half.
Strain the liquid through a sieve (and muslin if you want a very clear sauce) into a smaller pan on a gentle heat slightly off centre. Skim as the impurities rise to the surface and drift to the side. Reserve the meat and discard the veg and herbs.
Once the liquid has reduced to a saucy consistency, adjust the seasoning and acidity (you can use vinegar or lemon, though more than a few drops of each will be quite noticeable). Warm the meat through in the sauce. Serve with a suitably absorbent carbohydrate.
