You can enjoy fish and chips with tartar sauce (though in classical French cuisine that would only be served with breaded fish) or ketchup. My favorite is 'ladling' Salad Cream on the chips with Malt Vinegar and HP Sauce mixed with a little Malt Vinegar to make a sauce similar to the one they serve on the fish in Scotland. Here's a link to them if you can't find them at your local grocery store. They aren't expensive and really add to the dish!...
Part 1
Part 2