Step #1 In a mini-processor, puree marinade contents.
Step #2 Pour marinade over steaks & marinate in refrigerator 1/2 hr.
Step #3 Meanwhile, boil potatoes just until al dente & slice thin.
Step #4 Spray a baking dish with olive oil spray.
Step #5 Place sliced potatoes in baking dish & sprinkle a small amount of the marinade over them.
Step #6 Top with salmon steaks.
Step #7 Pour the rest of the marinade over the steaks & scatter the capers over the whole dish.
Step #8 Bake at 400F 10 mins & test for doneness--when cut into, flesh should be opaque but not yet flaking.
Step #9 If necessary, bake longer, testing every couple mins; it should not take longer than 15 mins.
Step #10 Place a bed of greens on each of two dinner plates, place half the potatoes & a salmon steak on each bed of greens, dribble any marinade left in pan over the top & sprinkle with parsley.