Salt the outside of the roast, no marinade or anything fancy.
Roast the beef uncovered on a rack at 450°F for 15 minutes.
Turn the oven down to 325°F and roast for another 45-60 minutes, depending on the size of the roast.
For a foolproof method, use an oven-safe thermometer and cook until it reads 120-125°F for rare or 130°F for medium-rare.
Let the roast sit for at least 10 minutes before slicing.
If using the roast for lunch meat, store it whole in the fridge and slice just before serving.
