The Pantechnicon is the Pablo’s almost favorite restaurant here in London. We go there to have lunch twice per month, sure. It is not my preferred one but it is true that you can feel you are really in London when you are sit down there.
You are enveloped in a British ambient: decoration, food, people, area… And you can have lunch/dinner/breakfast in the Pub (more casual) or in the dinning room (formal). The menu is not quite large but it has little changes each certain time. Meat and fish are good, always with British accent.
And the location is perfect “between Belgravia square and Sloane street”)
The Pantechnicon belongs to Cubbit House which has three restaurant more. I prefer The Orange (Pimlico), personally (menu is more “european”, it is more spacious, important because the buggy, and clients are younger than in The Pantechnicon).
Thomas Cubbit and The Grazing Goat (Marylebone) are the other two restaurants. I have never been in they but, by references, Thomas Cubbit is similar to The Pantechnicon and The Grazing Goat is more formal although with pub and dinning room as well.
I love decoration of all they! and in The Orange and The Grazing Goat you can hire rooms too.
Check the link below wether you are interested when you are visiting London!