Sous vide Galician octopus with watercress, radish and samphire tempura

Preheat a water bath to 75°C. Place the octopus in a vacuum bag along with the lemon peel (reserve the juice for later), parsley stalks, plenty of arbequina olive oil and some sea salt. Seal and cook for 4 and a half hours

Meanwhile, make the watercress purée. Cut off the stalks until you're left with mostly leaves, and set a few aside for garnish. Bring a pot of salted water to the boil and have a bowl of iced water ready. Blanch the leaves for 30 seconds then refresh in the iced water. Squeeze all the excess moisture from the leaves, then transfer to a blender with the garlic clove. Blitz until smooth, then season with salt and a dash of olive oil. Cover and set aside

Combine the cornflour and plain flour in a mixing bowl then slowly pour in the sparkling water, stirring constantly, until a smooth batter forms (do not overwork the mixture). Season with salt, then keep in the fridge until ready to use

Preheat an oven to 180°C/gas mark 4. Toss the radishes in the reserved lemon juice, some sea salt and olive oil, then roast for 10 minutes

Heat a deep-fat fryer or deep pan filled with oil to 180°C. Coat the samphire and caperberries in the cold tempura batter and place into the hot oil, frying for a few minutes until crispy (you may need to do this in batches). Drain on kitchen paper and keep warm

Once the octopus is ready, remove from the vacuum bag and pat dry. Place a griddle pan over a high heat until smoking hot. Separate the 8 tentacles – one for each plate – and pan-fry for a few minutes until crisp and coloured all over

To serve, place a tentacle on each plate with a quenelle of the watercress purée. Arrange 4 radish halves, 3 caper berries and pieces of samphire on each plate along with a few watercress leaves. Dress with arbequina olive oil and a sprinkling of hot smoked paprika, as true Galicians would!