1.75 pounds swordfish steaks (1–1.25 inch thick) – patted dry
1.5 teaspoons kosher salt
0.5 teaspoons black pepper – freshly ground
0.5 cups extra-virgin olive oil
2 lemons lemons – zested and juiced
3 cloves garlic – finely minced
1 teaspoons dried oregano
0.25 cups fresh parsley – finely chopped
0.5 teaspoons red pepper flakes
2 tablespoons warm water
1 tablespoons neutral oil – for oiling grill grates
Instructions
Finely grate the zest of the lemons, then juice them into a medium bowl; whisk in the garlic, dried oregano, red pepper flakes, and kosher salt, then slowly whisk in the extra-virgin olive oil followed by the warm water until slightly emulsified, and stir in the fresh parsley; transfer half to a small serving bowl and set aside for sauce, reserving the remainder as a marinade.
Pat the swordfish steaks dry and place in a shallow dish; season both sides evenly with black pepper, then pour the marinade over and turn to coat; marinate 15–30 minutes at room temperature.
Preheat a grill to medium-high (about 450–500°F); clean the grates well and oil them using the neutral oil on a folded paper towel held with tongs until shiny.
Shake excess marinade from the fish and lay it on the grill; cook 3–5 minutes per side until well marked and the center is just opaque with a hint of translucency, or an instant-read thermometer inserted into the thickest part reads 125–130°F; discard any leftover marinade.
Transfer to a warm platter and rest 5 minutes; spoon the reserved sauce over the fish and serve immediately.