Remarkably lean for so tasty a fish, tuna provides good amounts of healthy omega-3 fatty acids. It is also an excellent source of B vitamins. Swordfish has even less fat than tuna, with a good supply of niacin.
Combine the tomato purée, vinegar, oil, Tabasco sauce, oregano, ginger and a pinch of salt in a shallow bowl. Add the swordfish and rub the mixture into both sides. Cover and refrigerate for at least 1 hour.
Preheat the griller. Reserving the marinade, grill the swordfish 15 cm from the heat for 4 minutes. Turn the fish over, spoon on the reserved marinade, and grill for 4 minutes or until the fish is just cooked through.