Preheat oven to 350 deg. F

Place onions into a large roasting pan and place beef on top of onions.

Mix the remaining ingredients together and pour over the brisket.

Roast covered for 1 1/2 hours.

Reduce the heat to 320 and continue to cook for another 2 - 2 1/2 hours.

It should have a nice sticky glaze. If after checking, the sauce looks a little loose, then remove the lid, turn the heat up to 350 and allow to cook a little longer until the liquid evaporates and thickens up (this is called reducing) . Pesach time we want our meat to be saucy and easy to warm up, so remember not to allow it to dry out too much because you still have to warm it up. I would cook it Friday, allow to cool then slice and place back into dish with sauce. You really want your food to look as nice as it tastes.

However, if you find the sauce is drying out a bit then add a little water, scrape up all the bits off the bottom of the pan and stir until a glaze consistency is formed.

Pickled beef does take a little longer to cook through than fresh beef. So if you are using pickled beef increase the roasting time by another hour once you've reduced the temp to 320.