Season the beef roast with salt and pepper to taste. In a large heavy skillet, warm one tablespoon of olive oil over medium-high heat. Add the beef roast and sear the outside until browned on all sides. Can take up to 5 minutes on each side. Transfer the roast to a 3-1/2-quart slow cooker. Add the remaining tablespoon of oil to the same skillet and reduce the heat to medium. saute the onions, stirring, for about 7 minutes or until they are soft and golden. Add the garlic and thyme; saute, stirring, for abut a minute more. Pour in the coffee and balsamic vinegar, and allow to warm for about a minute; then pour the mixture over the beef in the crock pot. Cover and cook on high setting until the beef is tender, but not yet falling apart (usually about 4 1/2 hours). Transfer the beef to a clean cutting board and tent with foil to maintain its heat. Let the roast rest for about 10 minutes. Meanwhile, pour the juices from the slow cooking into a medium saucepan. Skim off the fat and bring the juices to a boil over medium-high heat. In a small bowl, blend together the cornstarch and water. Add the mixture to the saucepan and cook, whisking constantly, until the gravy has thickened slightly. Season with salt and pepper to taste. Remove the twine from the roast beef and carve. Serve warm with the gravy. Kitchen Staff Tip: Leftover roast beef will keep, covered and refrigerated, for up to two days; and it makes for a lovely second meal when warmed in the caramelized onion gravy. Posted to dailyrecipe@recipe-a-day.com by Recipe-a-Day on Oct 1, 1999,