Mix together the garlic, capers, anchovy paste, rosemary, lemon zest and juice, olive oil, and chopped tomato. Set aside and allow flavors to meld for 15 minutes.

Heat a heavy cast iron pan (well-seasoned) over high heat until very hot. Pat swordfish steaks dry with paper towels; lightly brush with olive oil. Season to taste with salt and pepper. Sear the steaks over high heat on both sides until done, about two minutes per side (flesh should be opaque; do not overcook). Plate, and top with reserved sauce and bread for sopping up sauce.