Melissa Clark / The New York Times
- 1½ pounds swordfish steaks, about 1-inch thick
- Kosher salt and freshly ground black pepper
- ½ teaspoon fennel seeds
- 1½ tablespoons olive oil
- 1 tablespoon butter
- 2 garlic cloves, minced
- Finely grated zest of ½ lemon
- ¼ teaspoon crushed red chile flakes, more to taste
- 1 tablespoon fresh lemon juice
- 2 teaspoons chopped fresh fennel fronds
- Lemon wedges, for serving
Using a sharp knife, cut the skin off the swordfish, then cut the fish into 1-inch cubes. Season fish cubes generously with salt and pepper.
Using a mortar and pestle or the flat side of a heavy knife, lightly crush the fennel seeds to release their flavor.
In a skillet large enough to hold all the fish cubes in one layer, heat the olive oil and butter over medium heat until the butter melts. Add the fish to the pan and let cook, turning the fish and basting with the oil and butter, for 3 minutes. Stir in the garlic, fennel seeds, lemon zest and chile flakes and continue to cook, stirring gently so as not to break up the fish cubes, until the fish is just cooked through, about 2 minutes longer. Gently stir in the lemon juice. Taste and add more salt and chile flakes if desired. Garnish with fennel fronds and lemon wedges.