kosher salt and freshly ground black pepperto taste
lemon wedgesfor serving, optional
To make the green olive tapenade, combine olives, capers, olive oil, fresh lemon juice and zest, parsley, garlic and anchovy fillet in the bowl of a food processor; pulse just until the olives are finely chopped. Season to taste with pepper. Transfer to bowl; cover and refrigerate until ready to serve.
Preheat your grill to medium-high (400˚F).
Pat swordfish steaks dry and place on a plate. Rub generously with olive oil and season with kosher salt and pepper.
Brush grill grates with oil just before adding swordfish steaks in a single layer, leaving a little space between each. Grill steaks with the lid down 4-5 minutes, depending on thickness. Using tongs or a thin, metal spatula, gently flip each steak. Grill 4-5 minutes more (again with the lid down) until just opaque or until the fish reaches an internal temperature of 145˚F.
Transfer swordfish to platter and spoon tapenade over. Serve with lemon wedges if desired.