To clean the vongole, plunge them into water and toss vigorously. Change the water and repeat.
With the tap running, rinse vongole handful by handful, rubbing the last sand particles from the ridges, set aside.
Heat a wok and add the wine. When wine is bubbling, add vongole.
Cover and steam over a medium - high heat, shaking occassionally to help vongole open.
Remove vongole as they open and place in a bowl.
When all have opened, strain cooking liquid through a fine sieve (muslin cloth) into a bowl. Set aside until needed.
Wipe out the frying pan and add butter, chopped garlic and chilli. Cook over medium - high heat.
Just before the garlic changes colour, add chopped chives and parsley and cook for a few seconds.
Add juices from vongole, return to a simmer and add some of the cornflour mixture. Stir until sauce thickens to avoid lumps. If sauce is too thick a little extra water or white wine to achieve desired consistency, if it is too thin, add more of the cornflour mixture and stir until sauce thickens.
Mix vongole through sauce.
Serve immediately. with plenty of crusty bread to dip in the sauce.