Preheat grill pan or outdoor grill to medium high heat.
Cube swordfish into generous bite-size chunks. Zest 2 lemons and pile zest on cutting board. Add 4 cloves garlic to zest and chop garlic. Add about a teaspoon of coarse salt to garlic and lemon and combine with flat part of the knife. Chop parsley and mix into garlic and salt. Add a generous amount of coarse black pepper to the pile and mix together with your finger tips. Coat the swordfish in a few tablespoons evoo ¿ enough to coat it evenly, just eyeball it. Slather the lemon zest and garlic mixture all over the fish. The evoo will make it stick. Pile the cubes onto metal skewers, it should fill 2 (12-inch) skewers. Set the fish aside for 10 to 15 minutes. Cut up 1 of the zested lemons into wedges and reserve.
Cut tuna steak into 6 small portions. Combine the zest of 2 oranges with the remaining 4 cloves garlic and chop. Add chopped rosemary to garlic and orange zest and combine with flat of knife. Add about 1/2 teaspoon coarse salt and about 1 teaspoon coarse black pepper to the mix. Place a few tablespoons balsamic vinegar and 1/4 cup evoo into a shallow dish. Add the orange-rosemary mixture and mix together. Add the fish and coat evenly in dressing and let stand 10 to 15 minutes. Peel oranges and slice into disks.
Throw together a salad, such as Panzanella with The Works, below, then go back to the fish.
When you are ready to eat, grill swordfish skewers 3 minutes on each side, 6 minute total. Slide from skewers and squeeze lemon juice over the fish. Cook tuna steaks 2 to 3 minutes on each side for pink, medium-rare fish, 4 minutes on each side for fully cooked fish. Serve tuna with sliced oranges alongside and scatter scallions over both. Each person should end up with 4 or 5 cubes of swordfish and 1 small tuna steak. Serve with salad.
Panzanella with The Works:
Combine all the salad ingredients in a large bowl and dress salad with lemon juice, red wine vinegar, evoo, and a splash of the hot pepper juice, then season with salt and pepper, to your taste.