Stir first 3 ingredients in a small bowl.
Arrange brisket in a large roasting pan; spread spice mixture evenly over both sides. Cover and refrigerate overnight.
Preheat broiler.
Uncover brisket.
Broil until brown, about five minutes per side. Turn brisket fat side up in pan.
Set oven temperature to 325°F.
Sprinkle leeks, onion, apricots, garlic, thyme and bay leaves around brisket.
Pour wine and beef broth over.
Cover pan with heavy-duty foil and bake brisket until tender, about 2 1/2 hours.
Uncover; cool for 1 1/2 hours.
Transfer brisket to work surface.
Pour juices into a large measuring cup.
Spoon off fat, reserving 1 tablespoon.
Thinly slice brisket against grain on slight diagonal; overlap slices in a 15x10x2-inch glass baking dish.
Spoon 1 cup of degreased pan juices over brisket; cover with foil.
Stir reserved 1 tablespoon of fat in medium saucepan over medium heat for three minutes.
Add remaining degreased pan juices; add remaining 12 apricots.
Simmer until sauce thickens and boils, stirring occasionally for about three minutes.
Season to taste with salt and pepper.
The brisket can be made two days ahead of time.
Cover brisket and sauce separately and chill.
Rewarm covered brisket in 350°F oven 30 minutes or 45 minutes if chilled. Rewarm sauce over low heat. Serve with sauce.