A gammon joint is a ham you finish at home. It is not a gammon steak, and it is not a Christmas showpiece unless you want it to be. Boneless Gammon Joint 1kg is a 1kg boneless joint, which is a sensible size for four to six people with leftovers for sandwiches. You will find it in gammon joint and the wider gammon range beside the steaks.
Boil then roast
Put the joint in a pan, cover with cold water, add a bay leaf, a few peppercorns and an onion if you have them. Bring to a simmer, not a rolling boil, and cook 30 minutes. Lift it out, peel off the skin if it is still on, score the fat, and sit it in a small roasting tin. Brush with a glaze — mustard and a spoon of honey, or just mustard — and roast at 180°C for 25 to 30 minutes until the fat is mahogany and a probe in the centre reads 68–70°C. Rest 15 minutes, then slice thick. Boiling first keeps the joint moist; roasting at the end gives you the crust people actually want on a plate.
Oven-only and slow cooker
If you do not want a pan of ham stock, roast from raw at 180°C for 30 minutes per 500g plus 30 minutes, so a 1kg joint is about 1 hour 30 minutes, loosely foiled for the first hour, glazed for the last 20 minutes. Probe, do not guess. Slow cooker: low for 5 to 6 hours with a cup of cider or water, then 15 minutes in a hot oven to colour the fat. The slow cooker will not give you crackling-style fat; the oven blast is what does that.
What to serve and what to buy with it
Mustard, parsley sauce, or fried eggs if it is a brunch joint. Cold, it is sandwiches for two days. If you want steaks instead of a joint, Gammon Steak 2x 8oz in gammon steaks is a 10-minute pan job, not a roast. A gammon joint also sits happily next to a pork loin in Sunday roast if you are cooking for a mixed table. Do not glaze for the whole cook; sugar burns and you will scrape black off a perfectly good piece of meat.
Simmer, glaze, roast, rest, slice. That is a 1kg boneless gammon, and it will feed more people than its size suggests.