Preheat the grill for medium direct heat grilling, 400-450 degrees F. Gather & prep all ingredients. It’s especially helpful to take care of the briney tomato salad at this point: Add the lemon juice to a medium bowl with the thinly sliced red onion & toss to combine. Set aside, & prep remaining salad ingredients (slice tomatoes, roughly chop olives & capers).
Add the olive oil, lemon zest & juice, garlic, cumin, coriander, smoked paprika, 1 teaspoon kosher salt, & ground black pepper as desired to a small bowl or jar. Whisk or shake to combine. Set aside, or store in an airtight container in the refrigerator for up to 1 week.
Place the cubed swordfish in a large bowl. Pour half of the prepared marinade over top. Set aside the remaining marinade, reserving it for serving. Toss the swordfish to coat it in the marinade. Thread the seasoned swordfish on skewers.
Once the grill is hot, clean the grates by scraping away any built up reside. Transfer the prepared swordfish kabobs to the grill. Grill over direct heat for 4-5 minutes per side, just until an instant-read thermometer inserted in the center of the fish registers 130 degrees F. Remove the kabobs from the grill & set aside to rest 5-10 minutes before serving.