Heat olive oil over medium-high heat in a heavy, oven proof cooking pot with a lid. When hot add beef brisket. Brown on all sides. Remove beef and set aside.
Deglaze pan with liquid of your choice.
Return beef to pot. Add Beef Brisket Simmering Sauce. Cover with lid and bake in preheated oven for 2-3 hours turning brisket several times. Brisket is done when meat is fork tender.
Serve sliced over mashed potatoes with remaining sauce.