Sarastro is rather a hard restaurant to describe and the easiest thing to do might be to search for it on Google Images.
It's a restaurant that mixes many different architectural styles: English, Gothic, Rococo, Ottoman and Byzantine opera boxes surround the main restaurant floor and Sarastro claims to be the first London restaurant to feature balconies.
On Sunday evenings there is string music to accompany the dining. It has featured on US Documentary World's Weirdest Restaurants.
You can see the menu here: www.sarastro-restaurant.com/menus.php
A two course Set Menu is £28.95 per person and a three course Set Menu is £32.45 per person, plus 12.5% service charge.
I've set a provisional date of Sunday 24th August at 18.00 to see how much interest there is in the event and once I've got an idea of numbers I'll try to secure a reservation with Sarastro on this date.