• Heat the olive oil in a large skillet or pan over medium-high heat.
• Season the roast on all sides with brown sugar, Kosher salt, and fresh ground pepper, gently rub the seasonings into the roast.
• Brown the roast on all sides until nicely caramelized (about 3 – 5 minutes per side). The added brown sugar aids in the caramelization and just slightly sweetens the whole mixture taking away any bitterness you may have.
• Place the roast into a large (6 quart) slow cooker.
• Add the onions, garlic, potatoes, carrots, and celery to the slow cooker pot.
• In a medium bowl, whisk together the balsamic vinegar, dry mustard, red wine, beef stock, Worcestershire sauce, bouillon paste, and chopped rosemary.
• Pour the liquid into the slow cooker. Stir to combine with the vegetables.
• Set the slow cooker on low and cook for 8 hours, or until the meat is tender and almost falling apart. The vegetables should also be fork tender.
• While the pot roast cooks, make the horseradish sauce by combining all the ingredients except the chives in a small bowl. Garnish with chives, cover, and refrigerate.
• Remove the roast and vegetables from the slow cooker and set them on a platter to rest.
• Turn the slow cooker up to high.

Making The Gravy

• Mix together the flour and butter to make a paste and add it to the liquid in the slow cooker. Gentle stir until the butter is melted and the liquid has thickened slightly.
• If you would like a thicker gravy, add an additional tablespoon of flour and butter.
• Garnish with chopped parsley
• Present the platter on the table. The meat should fall apart easily with tongs or slice the meat and serve with the vegetables, spooning the gravy over the plate as desired. Serve with horseradish sauce.