Heat 1 tablespoon oil in a large skillet over medium heat. Add onion, and sauté 5 minutes or until tender. Stir in garlic, and cook 1 minute. Add wine, artichokes, and capers; bring to a boil. Reduce heat to low, cover, and cook 5 minutes. Stir in tomatoes and 1/4 teaspoon salt. Cover and cook about 3 minutes or just until tomatoes are wilted. Remove from heat, and stir in parsley. Meanwhile, heat a large skillet over medium-high heat. Add remaining 2 teaspoons oil. Sprinkle tuna with peppercorns and remaining 1/4 teaspoon salt. Place tuna in skillet, and cook 2 to 4 minutes on each side or to desired degree of doneness. Serve with artichoke relish.
Pour: Chad Ellegood, wine director for Tru in Chicago, recommends a Cavalchina Bardolino Chiaretto or Alma de Blanco Godello Monterrei to enhance the bold Mediterranean flavors of this dish. The Cavalchina is a fresh rosé from northeastern Italy that offers a combination of fruit blossoms and light berries. The Alma de Blanco is made from the Godello grape, which is indigenous to northwestern Spain and complements its high acidity with ripe citrus flavors.