Preheat the oven to 325°F

Pat the brisket dry with paper towels. Place the brisket in a nonreactive roasting pan or a glass baking dish just large enough to snugly fit the brisket.

Mix the Coke, chili sauce, and dried onion soup mix in a bowl and pour it over the brisket.

Cover the baking dish or roasting pan tightly with aluminum foil

Roast the brisket until tender, about 30 minutes per pound (so figure 2 to 3 hours total, depending on the size of your brisket)
30 Minutes

Transfer the brisket to a cutting board and let it rest for at least 10 minutes,.
10 minutes.

Meanwhile, skim the fat from the surface of the pan juices and discard.

Pour the defatted pan juices into a gravy boat or, if a thicker consistency is desired, pour the juices into a saucepan and simmer until reduced slightly.

Trim any visible fat from the brisket, then thinly slice it against the grain.