Discard the rough outer leaves of the spring greens, wash the remainder thoroughly and trim away the stalks. Blanch in plenty of rapidly boiling salted water and drain in a colander.
Transfer to a serving bowl which has a close-fitting lid. Dress the greens with the olive oil, lemon juice, ginger and mustard. Toss to coat evenly. Scatter over the bonito flakes and put on the lid.
Remove the lid after 30 seconds and take to the table at once to alarm your guests with the sight of the bonito waving like something live and alien (the heat and moisture cause the light little flakes to ‘dance’).
© 1998 Alastair Little and Richard Whittington estate. All rights reserved.