In a small bowl, whisk together the olive oil, orange juice, sea salt and black pepper. Set aside.
Place fennel in a bowl and toss with about half of the dressing mixture until evenly coated. Set aside.
Arrange orange slices attractively on four salad plates. Mound the fennel mixture on top, divide and top with the smoked salmon, sprinkle with green onions and parmesan, then drizzle sparingly with the remaining dressing.