21-22 Warwick St London W1B 5NE http://www.nopi-restaurant.com    It’s not often that Gourmet Belly would choose to dine at 10pm on a Friday evening…but when it’s for a table at one of London’s hotly anticipated restaurant openings of 2011, the opportunity was too good to pass up.   NOPI is the new venture of Yotam Ottolenghi,…