Heat a large deep skillet or wide saucepan on a low heat and add the chorizo without any oil.
Cook for about 7–8 minutes, stirring occasionally, so the oil starts to come out of the chorizocubes and they colour all over.
Add the onions, garlic, sage and chilli and fry for 2 minutes.
Stir in the chopped mixed tomatoes, coriander, salt and pepper, cover the pan and simmer for 12 minutes, stirring a couple of times, until some of the tomato pieces have collapsed a little.
Add the rice and capers and stir well to coat. Pour over the boiling water, cover the pan and cook on a low heat for 12 minutes. Turn the heat off, but don’t move the pan or uncover for another 12 minutes.
Finally uncover, fluff up the rice and serve.