Classic versions of corned beef call for simmering, which doesn't produce the pan juices that serve as the base for pan gravy. You can't use the water, either, because of the salt transferred to it from the beef. You need to braise or roast corned beef in a 225-degree Fahrenheit oven until it reaches tenderness, or about 1 to 1 1/2 hours per pound, to produce a gravy base. You don't need to simmer the corned beef before roasting or braising it; instead, soak it in water for 2 hours per pound, changing the water out for fresh water every hour.

Braise the corned beef until tender in water or stock, and mirepoix -- chopped carrots, onions and celery. Cover the beef loosely with aluminum foil. Skim most of the fat from the braising liquid with a spoon.

Strain the braising liquid into a bowl and set it aside. Melt 1 tablespoon of butter in a saucepan over medium heat for every cup of sauce you want to make.

Whisk in 1 tablespoon of flour for every tablespoon of butter. Cook the butter and flour until it turns blond, about 4 minutes.

Add chopped vegetables to the pan. Minced garlic, shallots and mushrooms are the first choices for braise-based sauces because the braising liquid is already infused with the taste of carrots, onions and celery.

Cook the vegetables until caramelized. Pour the braising liquid in the pan and set the heat to medium-high. Whisk vigorously until the butter and flour coalesces in the liquid.

Simmer the sauce for about 5 minutes and adjust the seasoning with kosher salt and freshly ground black pepper. Finish with a flourish of freshly chopped herbs, such as tarragon, parsley, chervil and chives.

Roast the corned beef, covered in aluminum foil, for 2 hours and then remove the foil; finish roasting with the foil off until the fat cap on top crisps, about 30 more minutes. Take the corned beef out of the pan and cover it loosely with aluminum foil.

Skim most of the fat and any aromatics from the rendered juices in the pan. Place the pan on a stove burner and set the heat to medium.

Add vegetables, such as minced shallots and garlic, and saute them until caramelized and sizzling. Deglaze the pan with 1 cup of combined wine and stock.

Simmer the wine and stock until it reduces to 1/2 cup; whisk in about 1 tablespoon of equal parts fat and flour rolled into a ball, a pinch at a time. Alternatively, whisk in a couple of tablespoons of heavy cream.

Cook the corned beef gravy until it's thickened, about 2 or 3 minutes, and adjust the seasoning with salt and pepper if needed. Finish the sauce with a flourish of freshly chopped herbs and serve it over the sliced beef.