I tried to post this before but did something wrong, so again:
I am looking for a restaurant for lunch around St Pauls. If sunny I would love to sit outside or with a good takeway in a park in this area.
I am also looking for a place to lunch around Sloane Square/Sloane Street/ Duke of York Square.
Is there a nice place around Green Park to have a light meal or a tea (I love Fortnum but want to try something else).
Finally, is it possible for a woman to have a nice dinner alone after a concert in St Martins in the Fields? Where?

As for the others, St Pauls has lots of "City brasserie" style restaurants which you can browse and choose, as do the other areas.

Let me make a specific recommendation for The Wolsey - opposite the Ritz (bar entrance) - reasonable prices, and one of the hottest spots this season.

On Piccadilly,east of the Green Park tube station, is a Richoux. It serves a full menu all day, including afternoon tea items. It's not haute cuisine, but price is right, location is good (there are several) and food is reliable. Scones surprisingly good.

Please don't go to Richoux, the food is overpriced, and bland, you can do so much better!

It's for tourists only!

Nice lunch at Simply Nico's on Sloane Sq.