Roast the beef a day ahead; chill. Serve at room temperature.
Preheat oven to 400°. Sprinkle beef with pepper. Cook in hot oil in a skillet over medium-high heat, turning occasionally, 5 minutes or until browned on all sides.
Stir together salt and 1 cup cold water. Spread half of salt mixture in a rectangle (slightly larger than beef) in a large roasting pan; top with beef. Pat remaining salt mixture over beef, covering completely.
Bake at 400° 45 to 50 minutes or until a meat thermometer inserted into center registers 145°. Tap crust with a spoon; remove crust. (Beef will keep cooking if crust remains on.) Transfer beef to a cutting board. Cover loosely with foil; let stand 10 minutes. Brush off excess salt; slice beef. Serve beef in rolls with pesto.