Spicy Ginger Lime Vinaigrette: In a food processor or blender, add all ingredients except olive oil. Process until well blended. With blender on slow, add oil in a slow steady stream until fully incorporated and the vinaigrette has emulsified.
For Service: Carefully split open each half of pita to form a pocket. Stuff each pita half with 1/4 cup shredded lettuce. Place 1/2 cup thai tuna salad on top of lettuce in each pita half.