Heat the olive oil in a large saucepan and fry of the chorizo until crispy. Remove the chorizo and set aside.
In the same pan add 1 extra tablespoon of olive oil and add the onion, carrot and celery. Cook until translucent. Add the tomatoes and spinach and cook for a few mins. until the spinach has wilted. Add the paprika, season and then add the cooked chorizo. Bring to a boil and then lower the heat to a simmer and cook for half an hour. (In the last 5 mins. stir through the olives).
To prepare the cannelloni, add two spoons of the sauce to a large bowl. Toss through your dried cannelloni tubes, ensuring they are well covered with the sauce. Set aside for the moment.
Prepare a baking dish which measures 18cm in diameter by filling it ⅓ of the way up with chorizo sauce. Very gently stack your cannelloni in an upright position, ensuring they fit snugly in the dish. Add any of the remaining sauce over the tubes and around the sides.
Top with grated feta and Parmesan and cook in the oven for 30-35 mins, until the pasta is cooked through. Allow to rest for 15 mins. before serving with a green salad.