Steamed vegetables (such as cabbage wedges, baby carrots and potatoes) and wholegrain mustard, to serve
Method
To make the pickling spice, combine all ingredients together and store tightly covered until ready to use.
To prepare the corned beef, put the kosher salt, sugar, garlic, thyme with the previously prepared pickling spice, and 1 litre of water in a pot. Bring to a boil over high heat, stirring to dissolve the salt and sugar.
Remove from the heat and let the mixture steep for 5 minutes. Stir in the pink curing salt to dissolve, then add another 3 litres of cold water.
Transfer to the refrigerator to chill for at least 2 hours.
Put the beef brisket in a lidded, high-sided, food-grade plastic or metal container just large enough to contain the meat. Pour in enough of the cooled curing liquid to cover the meat, weighing it down with small plates if necessary, to keep the beef submerged beneath the brine.
Cover and refrigerate for 5 days, turning the meat over after 2 or 3 days.
Once the beef has been cured, remove the meat from the liquid and place in a pan large enough to just contain it. Reserve the curing liquid for now.
Rinse the meat in 2-3 changes of water and drain.
Strain the herbs, spices, and garlic from the curing liquid and discard the liquid. Add the herbs and spices to the pan with the meat and cover by 5cm of water.
Add the onion, celery, and carrot and just bring to a simmer over medium to high heat.
Cover, then reduce the heat to maintain the barest possible simmer, and cook for 3-4 hours until very tender but not yet falling apart (a carving fork should slide easily into the meat).
Carefully transfer the corned beef to a chopping board and, using a sharp knife, thinly slice across the grain.
Serve each portion moistened with some of the cooking liquid (reserve enough cooking liquid to reheat any remaining beef) in a wide-rimmed serving bowl with some steamed vegetables and garnish with the celery leaves. Have a separate pot of wholegrain mustard so that guests can help themselves.
