This is a combination of a half dozen different recipes that turned out even better than I expected. It's delicious and easy to make, but it takes a lot of setting time. Prep time DOES include marinating time!
Carefully slit just one end of the Cryovac bag, and remove the brisket, saving the bag.
Rinse off the brisket, trim off any surface that looks like age, but leave on as much of the fat as possible, rinse again, and set aside.
Rinse out bag, and set aside.
You will be using it to marinate the meat if you don't have any giant food-safe bags.
Alternately, you can use a roasting bag, such as the ones made by Reynolds.
Do not use a garbage bag.
They are not food-safe!
Combine all of the liquid ingredients in a small bowl, except for the olive oil, and stir to combine.
Add all of the dry ingredients, and stir to dissolve whatever is likely to dissolve.
Start with the minimal amounts of spices, and work your way upward, stirring and tasting as you go.
The marinade should be quite spicy!
Whisk the olive oil into the marinade.
Return the brisket to the Cryovac bag, and add the marinade, letting it drizzle down the sides of the meat.
Squeeze out as much air as possible, and staple the end shut; the easiest way to do this is to fill the sink with water and let the water help do the squeezing.
Massage the marinade into the meat, seal the Cryovac bag into a garbage bag to contain leaks, and it WILL leak!
Place in the refrigerator, and marinate in refrigerator for at least 2 days, preferably longer, up to 5 days, massaging and turning over 2-3 times a day.
Fold together the edge of 2 large pieces of heavy-duty foil to make a single piece large enough to enclose meat.
Place the meat and marinade on the foil, seal it in, folding up all edges to seal.
Alternately, place meat and the marinade in a large roasting bag, squeeze out air, and close the bag (I thought of this after the fact, of course!).
Place meat on a rack in a roasting pan, fat side up so it will self baste, and roast in a 250-275 degree F for about 4-5 hours, until it reaches an internal temperature of about 130 degrees F on an instant-read thermometer.
Carefully cut open the bag to expose meat, being careful not to burn yourself with the hot juices.
Poke a couple hole in the bottom to let juices drain into the pan, and pull out bag or foil from under the meat, letting meat rest on the roasting rack.
Return to oven, and continue roasting until internal temperature of meat reaches 150 degrees F, about another 1 hour or less.
The meat will be pretty well done, but it will still be juicy due to the slow cooking.
Remove roasting pan from oven, and allow brisket to rest at least 15 minutes before cutting.
Trim off and discard all external fat before carving across the grain.
Strain and degrease the pan drippings to use for jus or gravy.
The drippings will be WAY TOO SALTY and SPICY to use as-is, so dilute to taste with low-sodium canned chicken broth and water before using or freezing.
I ended up needing 2 cans of chicken broth and 4 cups of water to dilute 4 cups of drippings, and the jus was still very tasty!