In a small pan, heat the butter and sugar until melted.
Add the redcurrants, cook for a minute or so then squash with the back of a wooden spoon.
Add the quinoa, capers and parsley and cook for the further 2 minutes.
In a separate pan, heat the oil then fry the mackerel fillets for about two minutes on either side until cooked. Remove the fish from the pan onto a warmed plate.
Quickly add the quinoa mixture to the pan that had fish in, scraping off any bits that had stuck to the bottom.
Serve with watercress.
Recipe by The Eating Tree at http://www.theeatingtree.com/2015/06/27/mackerel-with-redcurrants-and-quinoa/