This slow-baked ham is a revelation. Instead of being boiled then transferred to a hot oven to be glazed, I cook it so, so slowly in the oven then remove to glaze and put the joint briefly back in a very hot oven. The meat is astonishingly tender and carves into thin slices with ease; there is also very little shrinkage, and no wrangling with large joints of meat in boiling liquid. If the 12-24 hours’ cooking doesn’t suit you, you can cook it for 5 hours in a 180C/160C fan/gas 4 oven instead, before glazing.