This recipe works well with any meaty fish.

Ingredients   
3  pounds 1-inch-thick swordfish steaks, cut into 8 pieces 
Salt and freshly ground black pepper    
1/2  cup plus 1 tablespoon extra-virgin olive oil, plus more for brushing    
1/4  cup pitted oil-cured olives    
1  small clove garlic, peeled    
1 1/2  cups loosely packed arugula leaves    
1/4  cup fresh flat-leaf parsley leaves  
1/4  teaspoon dried oregano    
12  small leeks, well washed
 
Directions
1. Arrange swordfish steaks in a shallow baking dish, season well with salt and pepper, and coat with 3 tablespoons olive oil. Let marinate at room temperature for up to 1 hour, until ready to grill. (Or marinate longer in the refrigerator, and return fish to room temperature before grilling.) 

2. Heat a grill or grill pan until very hot. Meanwhile, to make pesto, combine olives, garlic, arugula, parsley, oregano, and salt to taste in the bowl of a food processor. With machine on pulse, slowly add remaining 6 tablespoons olive oil. Add 1 1/2 tablespoons hot water, pulsing, until coarsely puréed. Set aside. 

3. Place fish and leeks on grill. Cook for about 5 minutes; remove leeks from grill, then turn fish. Cook fish for another 5 minutes or until nearly cooked through; remove from grill, and transfer to a shallow serving dish. 

4. Arrange leeks on a serving platter, and place fish on top. Spoon pesto over hot fish, turning fish to coat well. Pour juices over fish, and serve.  Serves 8.

Source:  marthastewart.com    Photo: Thibault Jeanson