Here is my grandmothers recipe (she always brings a brisket in her carry on when visiting -we're wierd)

Texas Style Brisket

1 4-5 lb brisket
1/2 c oil
2T worcestershire sauce
1t salt
1 clove garlic pressed
juice of 1 lemon

Marinade in above mixture for 4 or 5 hours, turning once. Remove brisket to a 9 x 13 inch baking pan, cover with foil. Bake at 325 degrees just until tender (1 1/2 to 2 1/2 hours). prepare grill to high heat and add mesquite chips if desired. Put pan over hot coals or gas fire and reduce meat juice (if too moist) or add marinade (if too dry) depending on the meat. Finish cooking on grill to desired doneness.

You can cook the brisket on the grill entirely, but it does use up a ton of propane.