After looking at Mansion House of City of London, have a meal at Laduree. The varied menu based on French cuisine is what you are offered at this cafe. Order perfectly cooked macarons. Good tea or great coffee will make your meal better and you'll surely come back.
Most users mention that the staff is gracious. Fabulous service is something guests appreciate here. Laduree was rated on TripAdvisor, it received 4.5.