Combine the octopus, crushed garlic, smoked paprika, olive oil and lemon juice in a non-metallic bowl. Cover and refrigerate.
To make sofrito, heat oil in a large deep, heavy-based frying pan or paella dish over a medium to low heat. Add onion and garlic. Cook, stirring, for 5 minutes. Add capsicum, tomato, smoked paprika, bay leaves and 1 teaspoon of sea salt. Cook, stirring, for 5 minutes. Add chorizo and cook, stirring for 10 minutes.
Stir through rice. Add the wine, stock and saffron. Bring paella to the boil without stirring. Cover with a sheet of baking paper and a tight-fitting lid. Simmer gently for 20 minutes over a low heat.
Add the octopus and peas to the paella. Cover and cook for a further 3 minutes.
Add the lemon, juice, scatter over the parsley and serve.