Not only is prep quick and easy for this marinated roast, but it is a good way to plan leftovers and use the remaining meat in a dish like Beef with Broccoli.
In a small bowl, prepare the marinade by mixing together the dressing mix, oil, and lemon juice. Marinate steak in marinade overnight (or all day) in refrigerator.
Grill or broil on medium heat about 5-7 minutes per side until done. Slice thinly across the grain and serve.