How to Make It
In a small frying pan, toast the pine nuts over moderately low heat, stirring frequently, until golden brown, about 5 minutes. Or toast them in a 350° oven for 5 to 10 minutes.
In a large nonstick frying pan, heat the 1/2 tablespoon oil over moderate heat. Sprinkle the swordfish with 1/4 teaspoon of the salt and the pepper. Add the fish to the pan and cook 4 minutes. Turn and cook until the fish is just done, 2 to 3 minutes longer. Remove. When the fish is cool enough to handle, cut it into 1-inch cubes.
Wipe out the pan. Add the remaining 1/4 cup oil to the pan and heat over moderately low heat. Add the garlic and cook, stirring, for 1 minute. Stir in 1/4 cup of the mint and remove the pan from the heat.
In a large pot of boiling, salted water, cook the penne until just done, about 13 minutes. Drain and toss with the swordfish, the garlic-and-mint oil, the pine nuts, the remaining 1/4 cup mint, and 1/2 teaspoon salt.
Variations You can use tuna in place of the swordfish. Cook the tuna a few minutes less than the swordfish so that it's still pink inside.