Heat the oil in a large frying pan (skillet) on a medium heat. Add the chorizo and cook for 1-2 minutes on each side until lightly browned and crisp. Remove from the pan with a slotted spoon, place in a bowl and cover.
Add the chopped onions to the pan and cook for 5 minutes, stirring often, until softened. Add a pinch of salt and pepper, the red and yellow pepper slices and the garlic. Cook for a further 2 minutes.
Add in the rigatoni, then pour in the stock, tinned tomatoes and tomato puree. Stir together, pushing the rigatoni under the liquid. Bring to a gentle simmer, then cover the pan with a lid or foil and simmer gently for 10 minutes.
After 10 minutes, carefully remove the lid and give everything a stir. Add the cream, spinach, mozzarella and parmesan. Stir together, the arrange the cooked chorizo on top (to heat through) and cover. Simmer for a further 2-3 minutes until the pasta is cooked through, the spinach wilted and the cheese melted.
Remove the lid and arrange the chopped tomatoes on top, then sprinkle with black pepper, chopped parsley and grated parmesan.