Instructions

1. Heat oven to 425°F. Combine onions, Brussels sprouts, oil and 1 teaspoon salt on metal baking pan; toss to coat. Set aside.
2. Combine thyme and pepper; reserve 1 teaspoon thyme mixture for sauce. Press remaining thyme mixture evenly onto all surfaces of beef roast.
3. Place roast on rack in shallow roasting pan. Insert ovenproof meat thermometer so tip is centered in thickest part of beef. Do not add water or cover. Place vegetables in oven with roast. Roast beef in 425°F oven 35 to 40 minutes for medium rare; 45 to 50 minutes for medium doneness. Roast vegetables 45 to 50 minutes or until tender and lightly browned.
4. Meanwhile, prepare sauce. Combine vinegar and shallots in small saucepan; bring to a boil. Reduce heat; simmer 3 minutes. Stir in cranberry sauce; bring to a boil. Reduce heat; simmer 6 minutes to blend flavors, stirring occasionally. Remove from heat; stir in reserved 1 teaspoon thyme mixture and remaining 1/4 teaspoon salt. Keep warm.
5. Remove roast when meat thermometer registers 135°F for medium rare; 150°F for medium. Transfer roast to carving board; tent loosely with aluminum foil. Let stand 15 to 20 minutes. (Temperature will continue to rise about 10°F to reach 145°F for medium rare; 160°F for medium.)
6. Carve roast into slices; season with salt, as desired. Serve with vegetables and sauce.