Directions

1. Preheat oven to 425°F. Place a wire rack in a shallow roasting pan. Line a rimmed baking sheet with foil. In a small bowl combine pepper, garlic and thyme; set aside.
2. Place beef on rack in roasting pan. Brush with 2 tablespoons of the mustard and sprinkle with 2 tablespoons of the pepper mixture, patting it into the mustard.
3. Add remaining 1 tablespoon mustard plus oil to remaining pepper mixture. Drizzle on Brussels sprouts and sweet potatoes; toss to coat. Spread vegetables on baking sheet.
4. Place pan with beef on upper oven rack. Roast 20 minutes. Reduce heat to 325°F. Place pan with vegetables on lower rack. Roast beef and vegetables 1 1?4 hours or until an instant-read thermometer inserted into the beef registers 145°F (medium-rare). Remove beef; let stand 10 minutes. Remove vegetables when tender. Slice beef against the grain and serve with vegetables.