The crisp and slightly sweet flavour of watermelon makes it an ideal vehicle for salad dressings. This is a decorative and refreshing salad.
Thinly slice the watermelon in medium-sized pieces, removing any pips. Remove the peel from the slices. Lay the watermelon slices in a shallow dish or roasting tin lined with kitchen paper. Slice the onions as thinly as possible into rings. Lay the onion rings on top of the watermelon slices. Cover the tin with clingfilm and leave for 30 minutes. Put the lemon juice, olive oil and a generous se