The perfect courgette is no fatter than your middle finger, with a wide-open yellow flower still clinging to its stem. Look for small, firm, unblemished courgettes whose skin has a healthy glow.
Dark green courgettes are easily available in Britain. Larger, pale green courgettes streaked with cream, a common sight during the summer in Italy and southern , are starting to appear in UK farmers' markets. Round courgettes, which are sometimes imported from , can also be grown successfully in Britain. Spaghetti squash, a rather bland-tasting vegetable whose flesh comes away in long, skinny strands when roasted, can sometimes be found in supermarkets.