Remove the intestines from the chorizo and cut into small cubes. Cut the red onions into small cubes and fry them together with the chorizo cubes and a dash of olive oil in a large pan.
Press the garlic and fry together with the sliced olives for about 1 minute. Cut the tomatoes into small pieces and add them complete with seeds and skin. Bring to the boil and simmer over a low flame for 30 minutes until the skin comes off the tomatoes.
Then add a good pinch of freshly ground black pepper and stir well. After another 5 minutes the sauce is ready.
Seasoning is not really necessary, as the chorizo and olives already bring everything with them.
All types of pasta go well with it and of course a coarsely grated Grana Padano or Pecorino piece. Also recommended cold as a spread on lightly toasted baguette.