This is a very Spanish dish. We cook it in Summer when tuna fish is 'in season'. Broadly speaking there are three main ways to eat tuna in Spain: in marmitako (see our recipe http://www.mumandsons.com/2013/07/marmitako.html), as they do in the North; 'encebollado', as they do in the South; and with tomato sauce (see recipe http://www.mumandsons.com/2014/07/tuna-with-tomato-sauce.html) as they do all over Spain. We like tuna so much that the white tuna from the North Cantabric sea is called 'bonito' (i.e. beautiful) and it is indeed a very beautiful fish.
- a thick steak of tuna for every three people (cut in not too small squares)
- a generous amount of olive oil (8 to 10 table spoons)
- 4 onions (sliced or just chopped in little squares)
- two cloves of garlic (sliced)
- a bay leaf
- a pinch of sweet paprika (pimenton dulce)
- three quarters of a glass of water
- two table spoons of wine vinegar (needless to say, Jerez is best)
- 4 table spoons of flour
- a pinch of oregano
- a tablespoons of chopped parsley
Salt the tuna and dust it with the flour (this is just to add a bit of consistency to the sauce, so no problem if the fish is not perfectly coated in flour). Heat the olive oil in a shallow pan (or a frying pan) over medium heat. Fry the tuna on both sides until it is golden (do not stir it too much or otherwise the fish will break; and if you are preparing this with a lot of tuna just do it in batches). Take out the fish and reserve.
In the same oil fry the garlic for two minutes over very low heat, then add the onion, increase the heat to medium for 4 minutes and then lower the heat to its minimum setting for another 15 more minutes. Then add the paprika, oregano, and half a teaspoon of the chopped parsley. You may need to add a bit more salt (just taste it). After a minute add the vinegar and finally the water. Put the tuna back into the sauce and let it all simmer for 10 minutes. Before you serve it sprinkle some parsley on top.
You can serve this with plain white rice or with fried potatoes (frankly much better and also more authentic than with rice)