Heat a grill or grill pan to medium-high. Rub the steaks with the garlic and a drizzle of EVOO. Grill the steaks, turning once, for 8 minutes for medium-rare. Season with salt and pepper.
In a small bowl, mix the butter and anchovy paste. Dollop on top of the steaks.
In a bowl, combine the tomatoes, olives, caper berries, onion, parsley and the remaining 2 tablespoons EVOO; season with salt and pepper. Top the steaks with the tomato salad.