2 cups baby spinach,
4 tablespoons capers, drained
4 cups crimini mushrooms, sliced
1 cup low fat feta
1 pound flank steak, pounded to an even thickness
1 tablespoon olive oil
1 cup onion, diced
1 pinch pepper
1/4 cup red wine
1 tablespoon rosemary, finely chopped
1 pinch salt