Using a vegetable peeler, cut paper-thin strips lengthwise from top to bottom of the parsnip, turning it as you work, making about 40 strips, about 10 strips per serving.
Heat 4 inches of oil in a large pot or electric fryer to 360ºF.
Drop the strips, all at one time, into the hot oil. Be very careful as the hot oil may splatter. Using a slotted spoon or spatula, gently stir the strips around in the oil until golden brown, about 1 minute. Remove and drain on paper towels. Sprinkle with salt to taste.
Divide into four equal portions and stack on top of each tuna steak.
Yield: 4 servings