If frozen, thaw the steaks 24 hours in the refrigerator. This is important - do NOT sous vide frozen steak.
Season the steaks, then vacuum pack.
Sous vide at 135 degrees for only 2 hours - any longer and the meat will become more tender but less flavorful.
Unpack the steaks, pat them dry, then cool them in the refrigerator for 10 minutes. This will provide more time when searing to develop that nice, brown crust without overcooking the steaks.