In a mixing bowl, combine the tuna, scallions, ginger, lemon zest, carrot, celery, capers, and herbs. Drizzle in 2 tablespoons of olive oil and add a bit more if the mixture is dry. Taste and season with salt as needed.

Place the fillo sheets in front of you lengthwise on a clean, dry work surface. Cut in half lengthwise and stack. Keep covered with a kitchen towel and place a second lightly dampened kitchen towel on top.

Remove the first sheet and brush with olive oil. Place a second sheet on top. Place a heaping 1 ½ tablespoons of the tuna filling on the bottom of the fillo. Fold the sides in and roll up to form a cylinder. Place seam-side down on the baking sheet. Continue until the filling and fillo are used up. Bake in batches if necessary at 375F for about 12 minutes, or until golden and crisp. Remove, cool slightly and serve, warm or at room temperature.