Preheat oven to 325°F.
Bring meat to room temperature. Pat dry, season with ground pepper. Heat olive oil in a large oven-proof pot or Dutch oven and sear meat on all sides. Remove meat from the pot and set aside.
Add more oil if necessary and sauté onions until translucent. Add ½ cup wine, and continue to cook, scraping up browned bits on the bottom of the pot.
In a small bowl, mix remaining ½ cup wine, ketchup and molasses or brown sugar. Add ketchup mixture to pot along with brisket.
Cover pot with lid or use heavy-duty aluminum foil to cover tightly. Roast for 2 hours. Remove pot from the oven, flip brisket, and baste with cooking liquid. Cover the pot and return to the oven to roast for 1 hour more.
Remove from the oven. Let cool, then refrigerate at least 8 hours or overnight.
To serve, slice brisket and arrange in serving dish with 1- to 2-inch sides. Cover with remaining gravy. Reheat at 300°F for 30 minutes before serving.
Recipe by Rachel Rosen
Want recipes like this delivered straight to your inbox? Sign up now for Jamie Geller's Weekly Newsletter.