Barbecued Brisket [Recipe]

We have been making this  brisket for many years.  It won the Dayton Kosher Barbecue Cookoff in 2012, and has been used for brisket fundraisers, bar and bat mitzvah's, and pot luck dinners.  The original recipe was adapted from one that was published in Joan Nathan's Jewish Cooking In America.  However, in that recipe, the author cites Marsha Pinson in The Cook Book, published by The National Council of Jewish Women.

Brisket looses a lot of liquid as it cooks.  Account for about 1/2 lb (uncooked) of meat per person.

Ingredients

1 1/4 cup 4-5 1/2 head 3 tablespoons 1 1/2 cup 2 tablespoons 1-1/2 tablespoon 2 teaspoons 1/2 cup

whole brisket (8-12 lb) liquid smoke, divided medium onions, chopped garlic, peeled and sliced brown sugar 16 oz bottle ketchup (Heinz) water Worcestershire sauce Dijon mustard celery seed margarine salt & pepper, to taste

1. Preheat oven to 325 °F.
2. Trim as much of the fat as possible from the brisket. Put brisket in a large roasting pan.  Rub with 2 tablespoons of liquid smoke, and cover with all of the onions and garlic.  Sprinkle with pepper.  Cover tightly with heavy-duty aluminum foil. and bake for 5 hours.
3. While the meat is cooking, combine the remaining 2 tablespoons of liquid smoke, brown sugar, ketchup, water, Worcestershire sauce, Dijon mustard, celery seed, and margarine in a 2 quart pot. Simmer uncovered for about 30 minutes. Season with salt and pepper. 
4. Uncover the brisket and transfer to a cutting board.  Pour out all of the liquid, but save as much of the onions and garlic as possible. Separate the brisket point from the flat, and remove as much fat as possible.  Slice each piece of meat thinly (across the grain), and return to the roasting pan.  Cover with the reserved onions and garlic.  Pour the sauce over the meat, and make sure the sauce gets between all of the slices.
5. Raise the oven temperature to 350 °F and reheat, covered, for at least 30 minutes.