The food at Ducksoup is ok and the service is very good, but not as good as some of the other tapas-type restaurants (Barrafina, Bocca di Lupo, Dehesa, Polppo, etc) in the area and too expensive for what it is.
During our lunch at Ducksoup we opted for the artichoke (6/10), foie gras on toast (8/10), ox-tail risotto (7/10), plaice (7/10), quail (7/10) and some cheese (8/10).
The wines are interesting at Ducksoup, in that they serve natural (not just organic) wines and therefore you can try wines that are difficult to find anywhere else.
We went for 4 glasses and in total the bill at Ducksoup was just under GBP 100, which is too much for what it is (GBP 70-80 would have been more appropriate).
Overall rating of Ducksoup: 7/10