Here is a recipe for cooking corned beef and cabbage---

as told to you by me---

Buy a nice corned beef brisket and don't trim it very much before cooking. Marinate at least overnight in brine of 1 gal water to 1/2 cup salt and 1/4 cup pickling spices. Add a few fresh thyme springs to the mix. You can use a cooler lined with a trash bag for this. Just add ice to the brine and keep the cooler closed.
To feed a crowd you'll need a large roasting pan to hold the corned beef. Buy about 1 pound per person, but not less than 4 pounds.
I like to cook the beef with lots of veggies, discard them and then cook fresh veggies to present with the beef--so here's a technique---don't be scared--it's worth it.

Put the corned beef in deep roasting pan with 3-4 cut up carrots, cabbage trimmings (see below), parsnips and onions- (you'll need more for the final dish--).
Add a few bay leaves, a few FRESH thyme sprigs, two cloves of garlic, a nice hand full of pickling spice and about a half pound of smokey bacon---slab is best but not essential.
Pour two bottles of lighter beer---Harp is perfect---nothing too hoppy or your juices will be bitter---over everything. Cover just to the top with water.
Cover with foil and bake in low oven - 300°--- for 5 hours.
At this point the beef should be real tender and the veggies will be totally mushy. If not, cook it a little more.
Remove from the oven and let it cool down right in the pan. When cool enough to handle, carefully remove the beef, strain and reserve the liquid and bacon and either discard the over cooked veggies or save them for a late night snack. Don't wash the pan---we are using it again.

Now, assemble the dish's second cooking.
Prep the veggies: Peel and wedge your carrots and parsnips into nice attractive finer sized pieces, at least 2 pieces each per person.
Trim and wedge your cabbage into 6 or 8 pieces, depending upon how big it is. Leave it on the core to keep it together (just trim the dark edges)
Peel at least two small boiling onions per person. In that same deep roasting pan put your fresh wedged cabbage ( at least one piece per person eating), small red potatoes cut in half, carrots, small boiling onions and parsnips. Cut the bacon into small pieces and sprinkle over the veggies. Add another spring of thyme and two bay leaves.
Trim any excess fat from the beef---I said excess, a little is good! Then fit the corned beef in there, too.
Skim any accumulated fat from the strained cooking liquid and pour over the beef, making sure that there is enough juice to cover the veggies most of the way---if not--add a little water. Pour one more beer over it all and cover with foil---cook in that same oven for another hour or until the veggies are perfectly cooked.
To serve, arrange some of each veggie on a deep plate or shallow bowl. Cut a chunk of corned beef---no need for thin slicin'---the beef will be fork tender by now. Drizzle on plenty of cooking liquid and serve with soda bread and butter on the side and---oh yes, some more beer.

Warm Regards,
Ric Orlando