2. Heat the olive oil in a small skillet over medium heat. Add the garlic and cook for 2 minutes. Add the tomatoes and capers, season with salt and pepper and cook for 2 more minutes. Add the balsamic and cook until it has reduced to a syrup, about 3 minutes, and set aside.
3. Meanwhile, season the swordfish steaks with salt and pepper. Grill or broil the fish on each side until it is cooked through, about 6 minutes per side.
4. Place each steak on a plate and spoon the tomato mixture over it.