To prepare the curry:

1. Place the onion, garlic, ginger and chili in a lightly greased skillet. Heat to medium and roast the ingredients until browned. This takes 4 to 5 minutes.
2. Transfer the roasted mix to an up-right blender, add the lime and curry leaves, and watermelon juice.
3. Blend the mix smooth, return to the pan and cook until a desired consistency.
4. Add the butter or ghee and whisk through.
5. Add the watermelon cubes, warm through and turn off the heat.

To prepare the prawns:

1. Pierce a toothpick through the backside, near where the head was attached, and pull it up. That way the vein will come out, leaving the prawn into shape.
2. Pull the vein out, wash the prawns and pat dry with kitchen paper.

To complete the dish:

1. Slice the potatoes lengthwise into very thin slices.
2. If you have a spiraler you can make strips in one go. If not, use a slicer.
3. Do not wash any more, the starch of the potato will keep it in place when rolled around the prawns.
4. Place the slices on a chopping board and cut into long thin strips.
5. Place a set of the strips, the size of a prawn, side by side against each other, top with a prawn and fold the strips around

6. Heat about 2 cm oil in a small pan to 350 F (180 C), reduce the heat to medium and fry the prawns crisp and golden. This takes, depending on the prawn size about 1 to 2 minutes. Drain on a rack or kitchen paper.

To serve the dish:

1. Place a serving of curry in the center of individual plates and top with two prawns each.
2. Garnish the plates with a sprig of basil and serve immediately after plating.