5 issues of BBC Good Food for £5
Heat a griddle pan. Rub courgettes in 1 tsp oil, season, then griddle until just soft. Set aside while you make the aïoli. Whizz egg yolks in a processor with the mustard, garlic and plenty of salt. Gradually add the oil until thick, then season with lemon juice. You can make this with a stick blender (see Know-how, above right). It will keep for a day in the fridge.
Season the fish. Heat a non-stick frying pan until very hot, add 1 tsp oil, then fry the fish, skin-side down, for 3 mins until crisp. Turn and fry the fish for just 30 secs-1 min more until it is cooked all the way through.
To serve, fold the herbs into the aïoli. Whisk 1 tbsp oil with the lemon juice, season, then use to very lightly dress the courgettes, mint and watercress. Pile onto plates, top with fish plus a dollop of aïoli, then scatter with herbs.