In the Buffalo, New York area, Beef on Weck, a thinly sliced rare roast beef (piled up to 6 inches high) on a freshly baked Kummelweck roll--is just about the best roast beef sandwich in America. Few restaurants outside the Buffalo area serve this sandwich--most don't even know what it is. It's a roast beef sandwich on a Kaiser roll topped with extra, coarse salt, and caraway seeds. It is the roll that makes the sandwich unique.
Preheat oven to 425 degrees F.
Rub roast with olive oil, salt, and pepper. Place roast on rack in a shallow baking pan, tucking the thin end under to make it as thick as the rest of the roast.
Bake, uncovered, 40 to 45 minutes or until thermometer registers 135 degrees F.
Remove from oven and transfer to a cutting board; let stand 15 minutes before carving. Reserve meat juice, carve meat into very thin slices.