Peel the potato and coarsely grate into a bowl. Add the lemon juice and toss to combine. Peel the parsnips and coarsely grate into another bowl. Place the grated potato on towel, and then gather up the corners to form a sack and twist tightly to wring out as much liquid as possible. Stir the potato together with the parsnips, flour, chives, salt, pepper and eggs until combined well. Fry in 1/2 cup vegetable oil in a medium skillet on medium heat, in two batches, about 2 minutes on each side.
Before serving, sprinkle with granulated sugar and torch, or place under the broiler to caramelize.