1 whole octopus (approximately 1kg/3lb), cleaned and prepared
For the green sauce
½ bunch fresh flatleaf parsley
1 small green chilli, chopped
½ bunch fresh coriander
3 garlic cloves, peeled
1 tsp cumin seeds, toasted and ground
2 tbsp olive oil
1 lemon, juice only
salt and freshly ground black pepper
Preheat the oven to 180C/160C Fan/Gas 4.
To make the salt-baked celeriac, put the salt, egg whites, flour and 150ml/5fl oz of water in a small bowl and combine to create a paste. Spoon some of the paste onto a baking tray and sit the celeriac on top. Completely cover the rest of the celeriac in the paste and bake for about 3 hours.
Meanwhile, cook the octopus. Heat the oil in a large saucepan and gently fry the onion, fennel, chilli and spices for 5 minutes, or until the onion is soft and translucent. Add the tomatoes and cook until the volume of liquid is reduced by half. Add the stock and reduce by half. Add the red wine, orange zest and juice and reduce by half again. Add the octopus, cover with a lid and simmer gently for around 1–2 hours, or until the octopus is very tender.
Carefully remove the octopus from the pan and leave to cool slightly. Return the pan to the heat and reduce the sauce by half. Meanwhile, remove the octopus legs and preheat a griddle pan. Griddle the octopus legs for 1–2 minutes on all sides.
To make the green sauce, blitz all of the ingredients together in a blender or food processor. Season with salt and pepper.
When the celeriac is cooked, leave to cool slightly then crack it open and scoop out the soft flesh.
Serve the octopus legs with the reduced sauce spooned over the top. Add scoops of the soft celeriac and garnish with the green sauce.