I do not have time the day of the party to cook the roast beef. My concern is if I cook it the day before, will it dry out and be tough the following day?
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America's Test Kitchen has a great recipe for Eye of Round which comes out perfectly medium rare. If you wrap it it will be fine. You can serve it at room temp. To serve it hot I hate sliced it thinly and rewarmed it briefly in beef stock.
Sorry - I don't hAte - I have sliced it thin.