I like to cook mine using the indirect method on an outdoor grill. The initial step is to brown it by leaving it uncovered on the closed grill for about 15 minutes. Then you reduce the heat so that the temp is about 350 degrees and shut one side of the grill off. You need a 4 burner to cook with that method. Cover the seasoned roast in the pan with aluminum foil and move the pan where it isn't over the fire.
Cook for the weight using the recommended time/pound. Then remove and let stand for 15 minutes. The meat will continue to cook. After letting the roast stand, carve and serve.