Italians, look away now! I know anguria is usually kept for the end of a meal but why not try to be different for once?
Here is a very quick and cooling watermelon appetiser which also looks pretty. You will have to assemble it just moments before serving, but you can cut the watermelon and keep it in the fridge, grill the courgettes [if not using frozen ones] and make your own pesto [if you wish] and chill it in advance.
First cut as many watermelon wedges as you have guests plus a few extra. Leave the rind on what will be the outside edge when the pieces are on the serving plate, as they will be easier to pick up that way. [In Italy, a greengrocer will cut the watermelon for you.] With a very small coffee spoon, scoop out all the seeds you can see, on both sides. Arrange the slices on a plate and top each one with a slice of grilled courgette, then add about 2 teasp pesto. [I do usually make my own but this time I didn't and sorry, Masterchef UK people - I don't do quenelles.] Top with a datterino tomato or half a cherry tomato and decorate with basil leaves.