In a small bowl, combine the Dijon, garlic, rosemary, lemon juice and zest and crushed red pepper. Schmear the steaks with this deliciousness and let them hang out in the fridge overnite at up to 2 hours minimum in the fridge.
Preheat the grill. Season steaks with salt.
When the grill is hot, brush and oil the grill. When the flames have dissipated, place the steaks on a hot spot on the grill. Brush with the excess marinade and move the steaks out of the flame if there is a flareup. Grill the steak for 4 to 5 minutes on each side for medium rare. Remove the steaks from the grill and let them rest 5 to 10 minutes before slicing. Serve immediately after slicing.