Preparation

• 1.For the aioli sauce, bake the potato in the oven at 180˚C/gas mark 4 until cooked through
  2.Meanwhile, start on the stock. Fill a large saucepan up with the 1.5 litres of mineral water and place the vegetable trimmings (fennel tops, carrot peel, celery peel) into the pan
  3.Rinse the fish trimmings and bones under cold water and add to the pan with the herbs, black peppercorns, salt, halved onion, leek and 1 1/2 of the garlic heads, sliced open. Cover the pan and simmer on a very low heat
  4.After 20 minutes, cook each vegetable one by one in the stock until tender. Set aside the vegetables once cooked, leaving the stock to simmer
  5.To prepare the cod, slice the cod into four chunks. Sprinkle a tray with coarse salt and lay the fish on top, sprinkle with more salt to cover the fish. Place in the fridge for half an hour
  6.Remove the potato from the oven and scoop out the flesh. Place the 1/2 a head of garlic in a pestle and mash with a mortar. Then, add the flesh of the potato, 2 tablespoons of the stock, an egg yolk, and keep on crushing the mix with the mortar
  7.Once smooth, start to incorporate the olive oil incrementally, like you would do for a mayonnaise. Season to taste and set aside
  8.Poach the cod chunks in the broth on a very gentle simmer. Add all the vegetables into the broth after 5 minutes of cooking
  9.Serve the cod with the vegetables and drizzle with the aioli sauce