Step 1Roughly chop watermelon flesh. Place into a food processor and process to a pulp. Strain through a sieve. Reserve juice.
Step 2Process strawberries. Add to watermelon juice.
Step 3Process peaches then strain through a sieve. Add juice to watermelon mixture. Stir until well combined. Pour juice into an airtight container, allowing room for expanding. Place into freezer.
Step 4Take frozen container on picnic. When ready to serve, juice will have partially thawed. Spoon into glasses. Top with lemonade or soda water.
