Cod, Three Cornered Leeks, Beefsteak Mushrooms

Cod, Three Cornered Leeks, Beefsteak MushroomsShane O'Neill, Aspect Photography

I love cooking this fish on the bone – using the tail keeps the fish really succulent. And when in season I swap the cod out for skrei, which is considered a culinary delicacy in many parts of the world

Serves 4


  • 4 x cod ‘osso buco’ style (200g)
  • 8 lemon wedges
  • Handful of three-cornered leeks or scallions
  • Seasoning
  • Butter
  • Oil
  • 600g riced potato
  • 50g butter
  • 40ml
  • three cornered leek oil (blitz neutral oil with green leaves and strain)
  • 70ml milk
  • 50ml cream
  • 500ml cod stock
  • 40ml lemon juice
  • 4 vegetable gelatine leaves
  • 1 lemon, zest only
  • 20g butter
  • 1 teaspoon oil
  • 1⁄2 clove garlic, crushed
  • 1 banana shallot, diced
  • 200g beef steak mushrooms


  1. Season the cod and heat a non stick pan with a drop of oil.
  2. Sear the cod skin side first, then flat on the bare fish meat.
  3. Add the lemon wedges and a knob of butter.
  4. Baste the cod with the butter and place it in the oven. Cook for 10 minutes on 175C/gas mark 4. Take it out and let it sit and warm /cook through gently.
  5. For the mash, boil milk, cream and butter and add to the riced potato. Fold this in and heat and season. At the last moment add the three cornered leek oil.
  6. For the mushrooms, in a non-stick pan, fry off the garlic and shallot in some oil. Add the mushrooms and toss them through the hot oil. Season and add small knob of butter to finish. Toss the blanched three cornered leeks through this and serve.
  7. For the jus,soak the gelatine in the stock and lemon juice, add the oil. Start reducing on a low heat. When it reaches the consistency of a ‘meat jus’ whisk in the butter and lemon zest.
  8. To serve, give the cod a quick flash back in the oven for 2 minutes. Plate it with a generous amount of mash together with the mushrooms, leeks and sauce.

Tip: You can replace the mushrooms with any ones you can get your hands on... shiitake – or beech mushrooms would be a great alternative.

Check out Martijn's other recipes below:

Crispy Organic Duck Egg and Purple Sprouting Broccoli

Potato Spaghetti and Land Caviar

McGraths Beef, Pearl Onion and Garden Lovage

Marinated Strawberries with Rice Puree and Tarragon