Grilled orange-rosemary swordfish with fresh tomatoes

2 navel oranges, scrubbed
4 4 ounces (120 g) each
1 tablespoon chopped fresh rosemary
2 tablespoons chopped shallots
Sea salt to taste
freshly ground black pepper to taste
no-stick cooking spray
1 teaspoon minced garlic
1 cup (8 oz/240 g) seeded and diced fresh tomatoes
1 tablespoon capers, drained
1 tablespoon chopped fresh basil, optional

1. Grate the zest from one of the oranges and measure out 2 teaspoons. Slice oranges in half, squeeze their juice and pour into a measuring cup.
2. Rub swordfish steaks with rosemary, 1 tablespoon of the shallots and half of the orange juice. Season lightly with salt and pepper. Set aside for a few minutes.
3. Light a charcoal fire or preheat a gas grill or stovetop grill pan.
4. Prepare the sauce
5. Oil the grill rack or pan. Grill the swordfish until browned on the first side, about 3 minutes. Turn over and cook about 3 minutes on the second side. Be careful not to overcook the fish, or it will be dry and tough.
6. Place the fish on a warmed platter. Reheat the tomato sauce and stir in the basil, if using. Pour sauce around the fish.