Preheat oven to 500?. Cobine garlic and OO in a small microwave safe bowl andcover. Microwave for 1 minute or until garlic is soft. Let stand for 5 minutes. Strain out oil into large bowl. Mash garlice to form paste then stir in thyme and 2 tsp of the strained oil. Preheat heavy bottom pan in oven for 5 minutes Add sweet potatoes, onions, 1/4 tsp of the salt and 1/4 tsp of the pepper to the bowl with the remaining oil and toss to coat well. Dry roast beef with paper towles and season with remaining salt and pepper. Place toast on preheated pan fat side down and roast for 5 minutes. Turn roast over and roast additional 5 minutes. Remove roasting pan from ove. Reduce heat to 350?. Coat top of roast with garlic thyme paste and scatter vegetables around roast. Return pan to oven and roast to 125? for med rare (about 60 minutes). Toss vegetables once or twice during cooking. When done, transfer roast to a plate, tent with foil and let rest for 15 minutes. Transfer veggies to serving platter, tent with foil. Place roasting pan on stove and add broth, bing to a boil. Using a wooden spoon, scrape browned bits from bottom of pan. Simmer stirring occasionally intil reduced by half, about 3 minutes. Add port and continue to boil until mixture is thick and glossy, about 2 minutes. Pour in any acumulated juices from the roast and simmer 30 seconds more. Slice roast, place on serving platter and pour sauce over meat.