Combine the lime, sour cream and chilli and set aside.
Using a spiraliser, available from specialty cooking stores, cut the potatoes into spirals. Place them in a bowl and add salt, set aside for about five minutes.
Drain water from the bowl and place the spirals onto a tray lined with grease-proof paper. Add a generous spray of olive oil and place in a 200C oven.
Turn the spirals after about seven minutes and remove after another seven minutes or when the fries are golden.