1. Chill soda can, till required.
2. Clean and deseed watermelon prior to use.
3. Refrigerate for 2-3 hours or till well chilled.
4. Save a couple of chunks of watermelon.
5. Chop these fine, keep refrigerated till required.
6. Transfer remaining chunks to a mixie.
7. Add all ingredients, except icecream soda.
8. Pour into 3 tall glasses, which may be previously chilled.
9. Pour a third of soda into each glass, just before serving.
10. Garnish with mint leaves.
11. Serve while soda is still frothing.

Making time: 15 minutes (except chilling time)
Makes: 3 servings
Shelflife: Best immediate