The best place for a glass of wine*. It's the perfect balance – not too formal, not too informal either. Food is consistently good. Lamb's Conduit Street is a little oasis in the midst of Bloomsbury. (*slightly overpriced)
The Garden is nestled behind walls and positioned close to the River Thames in Chelsea. The Thames location is no accident as back in 1673 the Worshipful Society of Apothecaries chose their Chelsea village site for its proximity to the river to make the most of its warm air currents. It also gave them a base to moor their barge, allowing them to conduct plant finding expeditions in surrounding areas and to teach their apprentices to identify plants.
Lots of traditional charming country pubs around the area, but it can a bit hit and miss. A really friendly one with amazing food (and a unusually large veggie selection…) is the Beehive in Epping Green; close to the Great Wood. It's friendly enough you dare going there by yourself with the paper and are not at the mercy of local rubbernecks ("the rubberneck" = person who stares at strangers without any sign of guilt)