Step 1

Cut watermelon into 4 thick slices, leaving rind attached.

Step 2

Place watermelon in airtight containers and freeze overnight.

Step 3

Meanwhile, place 4 x 1 cup-capacity freezer-safe serving glasses on a tray and place in the freezer to chill.

Step 4

Working quickly and using a fine grater, grate 1 watermelon slice into each serving glass. Return each glass to the freezer to chill as you go.

Step 5

Divide yoghurt among glasses and sprinkle with coconut, pistachios and lime zest. Serve immediately.