Here's a form to do a name lookup in Harden's restaurant guide; this is far and away the best restaurant guide in London, so this is handy. Note that you will need to log in (or be logged in) to the site for this to work; this is free, easy and spam-free, so do it immediately.
Note that you can also search the guide from a form on the Harden's site. However, that form works by POST, so it doesn't generate bookmarkable URLs; this form works by GET, so it does. This also means it can be turned into a keyword search.