I get tonnes when I google it - is there such a thing as an authentic receipe?
& whilst at it, same q for - Linguini al vongole...

What makes you think the recipes you get aren't authentic? It should be diced fat salt pork, onions (cooked in the pork fat till translucent but not browned), clam broth, potatoes (diced and simmered in the broth until done. big clams/quahogs (steamed open and chopped), and cream.
In the US there is spaghetti with white clam sauce and spaghetti with red clam sauce. Red clam sauce is a tomato sauce with clams and clam liquid. White clam sauce is oil, garlic, parsley, clams (steamed open and chopped) and the broth. Lots of garlic. Lots of bread on the side to mop up.
In both cases, after adding the clams just heat enough to warm them through or they'l be tough.
Asking for "Authentic New England Clam Chowder" is somewhat akin to asking for "Authentic Southern Fried Chicken." Everyone's grandmother knows the one, true authentic recipe and all others are bogus.
Vinny gave a rough outline, but there are recognized styles of the stuff. Ochef says, in answer to a similar question <blockquote>Quote
<hr>Among thousands of clam chowders, no more than three or four broad categories have taken on names that chefs or food snobs would agree on. There are two recognized types of New England clam chowder (the assertive chowder made with quahogs and seasoned with herbs and often garlic, and the sweeter, more subtle steamer, or soft-shell, clam chowder, which is less heavily seasoned). According to Jasper White, both include a creamy broth with clams, potatoes, onions, celery, and salt pork or bacon, but neither of these two varieties has an official name other than New England Clam Chowder.
Yes, there is Manhattan Clam Chowder, which some have characterized as vegetable soup with clams. It, too, has many, many varieties. In between — geographically and culinarily — there is is Rhode Island Clam Chowder, which has neither tomatoes nor milk, but a clear broth (although pitchers of hot milk are often served alongside for those who realize that Rhode Island is actually a part of New England).
In your zeal to understand chowder, you have fallen into the trap of believing that — like most things in our commercial society — everything in the food world is branded. There is no official Boston Clam Chowder, nor can we find any agreement about what particular variation of New England Clam Chowder it would refer to. That doesn’t mean, of course, that dishes by that name don’t appear on hundreds of restaurant menus inside and outside of Boston. Authentic Clam Chowder is either an oxymoron or it applies equally to any and all clam chowders ever made.<hr></blockquote>

Garlic in New England clam chowder just sounds like a category error to me. Celery is fine. I was going to mention bacon as a possible substitute for salt pork but I thought that might start a fight.

Um Vinny, you mentioned garlic yourself! There are lots of Italians and Portuguese in New England. Why wouldn't they put garlic in clam chowder?
Are you sure you didn't have New England clam chowder?
Where did you have it? We can't comment any further until that's been revealed.
I always liked what you get at Legal Seafoods until I discovered a place on Cape Cod that wins a lot of the titles at the various chowder festivals. Their version is the food of the goods. The problem is that chowder is ruined for me now and I'll never enjoy it again unless it is that good. Even in Boston and other places on the Cape it's not as good as that.
What's your recipe? Maybe if I try at home I'll be able to replicate it.