Combine olive oil with onions in 13 x 9-inch metal baking or roasting pan. Arrange roast on onion mixture. Season roast with salt and ground black pepper. Cut slits in roast and insert garlic.
Bake 20 minutes. Reduce heat to 350° and bake 55 minutes or until desired doneness. Remove roast from pan and let rest 15 minutes.
Meanwhile, over medium-high heat, stir Knorr® Classic Brown gravy mix blended with water and vinegar into pan, scraping up brown bits from bottom of pan. Stir until smooth. Add Spread and cook, stirring occasionally, 5 minutes or until gravy is thickened. Serve gravy with sliced roast beef.