And where do you buy it from? and what is it called?

All I know is chardonnay.

Chardonnay is not considered a dry white.

Probably the driest white is from the Loire (Nantaise region) called Gros Plant. It goes well with crustaceans.

You'll have to go to a specialist wine merchant, they don't sell those obscure wines in supermarkets.

Thanks for the info...so what are the driest wines I can buy in a supemarket?

Something like a chilean sauvignon blanc would be good, or if you can splash out a bit, a nice NZ marlborough sauvignon blanc. An italian Soave is dry too,

Yes, a Sauvignon Blanc, Chardonnay (is deffo classed as a dry) or a Muscadet.

Quite often there will be a number on the label or the price ticket. They range from 1-7

1 is very dry, 7 is very sweet (a dessert wine)

Muscadet, I'd have thought.
You need to serve it very chilled; ideally at least a day in your fridge.