Bone Marrow Gravy

Marrow is nature's own butter and it does something to gravy that dairy cannot quite match. You roast the bones for the stock as normal, but instead of throwing them away you scoop out the soft centre and beat it into the finished sauce. It goes glossy and rich and is very hard to stop eating.

Ingredients

Makes about 500ml, rich enough that a little does the job

• 1.5kg (3lb 5oz) beef marrow bones cut into 6cm lengths, ask for centre cut
• 500g (1lb 2oz) beef knuckle or rib bones for the stock body
• 1 large onion halved
• 1 carrot
• 1 stick celery
• 3 litres (5.25 pints) cold water
• 2 sprigs thyme
• 1 bay leaf
• 25g (1oz) plain flour
• 25g (1oz) butter
• 1 tbsp flat leaf parsley finely chopped, to finish
• 1 tsp sherry vinegar
• flaky sea salt and black pepper

Kit

• Roasting tin
• Saucepan
• Teaspoon for scooping marrow
• Fine sieve
• Whisk

Method

1. Heat the oven to 220C fan (240C conventional, gas 9). Stand the marrow bones upright in a roasting tin with the knuckle bones alongside and roast for 25 minutes. Marrow bones cook much faster than plain bones, so pull them out at this point before the marrow renders out completely and is lost.

2. Scoop the soft marrow out of the roasted bones with a teaspoon into a small bowl. It should be wobbly and translucent, like set butter. Cover and set aside at room temperature. Put the emptied bones back in the tin.

3. Return the tin to the oven with the onion, carrot and celery added and roast for another 25 minutes so the bones and vegetables all take on deep colour.

4. Tip everything into a saucepan, deglaze the tin with a little water, add 3 litres of cold water and bring slowly to a simmer, skimming as you go. Add the thyme and bay.

5. Simmer gently for 4 hours, never letting it boil. Strain, chill briefly and lift off the fat. You should have roughly 1.2 litres.

6. Reduce the stock in a wide pan to 600ml, which takes around 20 minutes and concentrates it properly.

7. Make a roux with the butter and flour in a separate pan, cooking for 2 minutes until golden, then whisk in the hot reduced stock and simmer for 5 minutes until smooth.

8. Take the pan off the heat and whisk in the reserved marrow in small pieces. It melts into the gravy and turns it glossy and slightly opaque. Do not boil it after this point or it will split. Add the vinegar, parsley, salt and a lot of black pepper, and serve at once.

Tips worth knowing

• Ask for centre cut marrow bones rather than the narrower ends. You get far more marrow per bone and it scoops out in one piece.
• Soaking the marrow bones in salted water for a few hours before roasting draws out the blood and gives you cleaner, whiter marrow and a clearer stock.
• Add the marrow off the heat. It is nearly pure fat and it will separate out into greasy pools if the gravy is boiling when it goes in.
• Parsley and vinegar are not garnish here. Marrow is very rich and both are needed to keep the gravy from feeling heavy.

Keeping and reheating

Best eaten the day it is made because the marrow can separate on reheating. If you must keep it, the gravy base without the marrow keeps four days chilled and three months frozen, then add fresh marrow when you reheat.

Questions people ask