4 (4–6-oz.) swordfish steaks (1"–1½" thick)
7 Tbsp. plus 1½ tsp. extra-virgin olive oil, divided; plus more for grill
1 large lemon
5 sprigs oregano, thyme, or marjoram, leaves picked, finely chopped
2 garlic cloves, finely grated
1 Tbsp. capers (not drained)
2 tsp. ground coriander
1 tsp. sugar
½ tsp. crushed red pepper flakes (optional)
Freshly ground black pepper
Pat four 4–6-oz. swordfish steaks (1"–1½" thick) dry with paper towels, then coat with 1 Tbsp. extra-virgin olive oil. Season both sides with kosher salt; set aside while you make the dressing.
Using a sharp chef’s knife, trim ends from 1 large lemon; slice into thick rounds and remove seeds. Very finely chop lemon rounds (peel, pith, and flesh) and transfer to a small bowl. (Alternatively, you can pulse in a food processor.) Mix in 5 sprigs oregano, thyme, or marjoram, leaves picked, finely chopped, 2 garlic cloves, finely grated, 1 Tbsp. capers (not drained), 2 tsp. ground coriander, 1 tsp. sugar, and ½ tsp. crushed red pepper flakes (if using). Stir in 6 Tbsp. plus 1½ tsp. extra-virgin olive oil. Season with freshly ground black pepper and more salt if needed.
Prepare a grill for medium-high heat; oil grate. Place reserved swordfish steaks on grill; cover and grill fish, turning once, until flesh is opaque and just cooked through (an instant-read thermometer inserted into thickest part should register 130°F for medium-rare) and steaks release easily from grate, 3–5 minutes per side. Transfer to a platter.
Spoon some dressing over swordfish and serve with remaining dressing alongside.