Supposing you made that ten-pound corned beef brisket (as outlined below) ... cut it in half after it has completed its brining process. You can freeze one half of it, or go ahead and cook it right away for supper.
But let's take your other five pound half, and turn it into pastrami. Shall we?
Trim the five-pound half for pastrami to leave about 1/8 inch of fat on it.
Now here's the spice mix, and it's very important:
2 TBSP ground coriander (this is really a signature flavor of pastrami right here!)
1/2 tsp red pepper flakes
3 TBSP coarse black pepper (very, very integral to the pastrami!)
So now we're going to combine all of our powdered spices to a large platter, and then coat all sides of our brined brisket. Be sure to pat all the spices on there real good, and get the spices as evenly as possible on all sides.
Then sprinkle a little hot pepper flakes on there, and then coat that course black pepper all over it, too. Make sure it sticks real good.
Preheat your oven to 240 F ... it's important to go with a very low, slow oven.
Lightly oil some heavy-duty foil ... a nice large piece ... and fold up all four sides and wrap your brined brisket into a nice tight package.
I use coconut oil for dang-near everything in the kitchen ... olive and sesame are close seconds.
Then flip over your wrapped brisket, and wrap it again.
And then, yes, wrap it again ... and again ... and again ... and again.
You are going to wrap your brisket real tight for a total of SIX times ... that's SIX layers.
Oh, by the way, only the first piece of foil needs to be oiled.
So anyway, now you're going to have this tight package, and that beef is going to be encased with all those delicious spices.
You are going to slow roast it for 5 hours ... using a casserole pan ... and after it has slow roasted
for five hours, you are going to set it out (unopened) until it cools.
And then, very important, you have to let it chill in the frig overnight.
Twenty four hours is even better.
Then you can finally unwrap it.
At this point there is a couple of things you can do with it, outside of the obvious:
1) If you don't want it as spicy ... you can wipe off the rib and slice it like that.
2) Leave the spicy rub on it, and put it in a hot oven for 15 minutes at 400F ... and that will kind of seal the crust on, and give your hot pastrami to slice.