In a large saucepan, heat the olive oil over a medium heat. Add in the garlic, shallots, herbs, salt, and peppercorns and cook for 5 mins while stirring frequently.

Add your Bordeaux wine to the saucepan, turn up the heat and allow to simmer until the liquid has reduced by two-thirds.

In a separate pan, add the smoked bone marrow to the beef stock and heat until the fats and liquids have rendered from the bone marrow.

Add this beef stock and smoked bone marrow to the wine mixture, keep the heat high and stir continuously until it reaches a rolling boil.

Once the mixture is at a rolling boil, keep it at that temperature and continue to cook until it has reduced by half and has started to thicken.

Strain the sauce through a sieve and into a clean saucepan; discard the herbs, shallots, garlic, and any unrendered bone marrow.

You want the sauce to be thick enough to coat the back of a spoon - if it’s not yet at that consistency, carry on reducing the sauce over a medium-high heat until it reaches the correct thickness.