Irish Spiced Beef is not the same as corned beef.
It is an Irish dish made from a cut of beef which is spiced and aged a bit, then cooked by simmering. Despite all the cooking, the inside comes out pink. It is often served with boiled potatoes or other root vegetables.
The cut of beef used is usually something like brisket or another cheaper cut of beef.
It is seasoned with a dry rub of brown sugar and spices, applied every day over a period of several days.
One of the ingredients in the rub used to be saltpeter (potassium nitrate), a preservative. Recipes now call for Prague Powder instead. Other ingredients used are sugar, cloves, salt, black pepper, thyme, marjoram, allspice or cinnamon, mace, finely-chopped onion (or shallot), and nutmeg. All dry ingredients are used in the mixture, no liquid. You mix all the dry ingredients into a rub, then add the chopped onion.
You rub the joint of meat with about 1/7th of the spice mixture. You then place the beef into a container (not iron), cover the container and place it in a cool spot. Each day, you apply another seventh of the rub, and turn the joint over. During the process, liquid will come out of the meat; leave it be.
At the end, you then simmer the joint until the meat is just about tender. You then change the water in the pot, and simmer another half hour. At this stage, you add root vegetables such as carrots, potatoes, parsnips, and onion, and cook them until they are half done. You then add stout to enrich the stock, and simmer for another 20 minutes.
It can be served hot or cold.
When serving cold, you drain the meat, then press it. To press it, put a colander on a plate or tray, put beef in the colander, put a weight on it, and let it stand for a few hours or overnight in the fridge.
Irish Spiced Beef is traditionally served at Christmas, particularly on Boxing Day or New Year’s Day, for an in-between meals snack as thin cold slices on buttered bread.
Most people now purchase theirs ready-made at the butchers at Christmas.
Most modern recipes advise doing the aging in the fridge.
Some modern receipes swap in treacle or honey for the sugar (even though traditionally it was an all-dry rub.)
Irish Spiced Beef was also made in the Scottish lowlands.
It became fashionable in England in the latter half of the Victorian Era.