If you're in King's Cross it is worth stopping by Bella Vita, a little cafe. They sell great Egg's Benedict and even writing about it is making me crave them. They are that good. And they serve them all day every day. It comes with the usual delicious sauce but you can also get extras added on like mushrooms and it comes with lettuce which is a bonus if you're health conscious.
With an indoor seating area and an outside seating area this place is fantastic.
The staff are always friendly and you can get coffee or cold drinks to go with your Eggs Benedict.
I've been going to this place for a few years and highly recommend it.