Try this method for the most amazing roast:
Take a cup of oil, add in any spices/ herbs you like (I do kosher salt, pepper, garlic powder, onion powder, paprika, ground mustard, a little adobo, some steak seasoning... whatever is around)
Rub meat all over with some of your oil mixture. Broil 15 minutes. Flip over, baste with some more of your oil mixture, broil another 15 minutes. Keep flipping, basting, and broiling 15 minutes at a time until internal temperature registers to your preferred level of doneness. If rewarming, undercook somewhat the first time. Since I like my roasts sliced thinly, I slice when cool then wrap tightly with foil before warming up. This has gotten rave reviews from anyone who's ever eaten by me.