Chateaubriand with a bone marrow sauce

Preparation time
less than 30 mins

Cooking time
1 to 2 hours

Serves
Serves 2

By Matt Tebbutt

For the crisp shallots

  • 2 banana shallots, unpeeled
  • 4 thyme sprigs
  • 12 tbsp olive oil

For the chateaubriand

  • 1 chateaubriand steak
  • dash oil
  • 1 head of garlic, halved
  • few thyme sprigs
  • 50ml/2fl oz Madeira wine
  • 30g/1oz butter
  • salt and freshly ground black pepper

For the sauce

  • 8 whole garlic cloves, peeled
  • oil, for frying
  • 100g/3½oz smoked pancetta, cut thickly into lardons
  • 10 button mushrooms, quartered
  • 2 tbsp button onions
  • 150ml/5fl oz port
  • 1 bay leaf
  • 1 thyme sprig
  • splash sherry vinegar
  • 150ml/5fl oz dark beef stock
  • 400g/14oz bone marrow pieces
  • salt and freshly ground black pepper

For the tarragon and parsley oil

  • 6 tarragon sprigs, leaves only
  • small bunch flatleaf parsley, leaves only
  • 200ml/7fl oz groundnut oil