Pour 1/2 cup Marie’s Red Wine Vinaigrette over steak and mushrooms, turning to coat with dressing. Marinate for 15 minutes.
Prepare grill for medium-high heat. Grill mushrooms 3 to 5 minutes, turning once. Grill steak to medium rare or to your choice of doneness. Let rest 10 minutes before thinly slicing across the grain. Slice mushrooms.
Divide greens between four plates. Top with steak and mushroom slices. Drizzle with remaining Vinaigrette; garnish with Parmesan.