Spray a deep frying pan 4-5 times with the low calorie oil spray, then add the onion and fry over a medium heat for 5 minutes until softened. Add the garlic and fry for a further 2-3 minutes. Stir in the paprika and squid and cook for 1 minute.
Add the chopped tomatoes and 100ml water. Bring to the boil then reduce the heat to a simmer. Cover and cook for 40-50 minutes until the squid is tender, stirring occasionally. Stir in a little more water towards the end of the cooking time if necessary.
Just before the stew is ready, heat a small non-stick frying pan until very hot. Add the sliced chorizo and fry for 2-3 minutes until browned and frazzled. Remove and drain on kitchen paper.
Stir the butter beans into the stew and season to taste with freshly ground black pepper. Serve in warmed bowls topped with the frazzled chorizo and chopped parsley.