Mix together the butter, chilli, coriander and garlic. Place on a double sheet of cling film and roll into a sausage. Place in the fridge to chill.
Place the each piece of cod in a sous vide bag. Take the chilled butter and cut 8 discs from it.
Place two discs of butter on top of each piece of fish and seal the bags.
Place the beans in another sous vide bag, add the garlic, lemon zest and olive oil. Season with salt and pepper. Give them a gently shake to cover the beans in oil. Seal the bag.
Fry the chorizo in a dry frying pan and fry until crispy. Add the halved tomatoes and warm through until they just start to soften. Season with salt and pepper and stir in the parsley.
Set the sous vide oven to between 60-65oc. Cook the fish and beans for 8-10 minutes, your beans may need a little longer if they are thick.
Place some of the ragu on the bottom of a plate, top with the green beans and the fish with its butter and sprinkle with fresh coriander.