There are a few places in london two resturants in earls court and one over in charlotte street just by goodge st station.
Its debatable how good they are some people think they are not up to much others like them. But if its just for some basic phill foods in a phill like enviroment then they should be fine.

All three resturants seem to do buffets where you can eat as much as you can,they looked worried when i went up for my fourth or was it fifth time as most seem to go up once but to me that kind of defeats the object of a eat as much as you can buffet.