1. Segment the Florida Grapefruit.
2. Create the salad dressing by mixing the extra virgin olive oil, salt and pepper.
3. Preheat the oven to 170C or 350F.
4. Toast the walnuts by spreading them across a baking tray and roasting in the oven for about 10 minutes or until crisp. Set aside to cool.
5. Place the Florida Grapefruit segments, watercress leaves, cos leaves, shrimp and walnuts in a large bowl.
6. Toss the salad with the dressing just before serving.