Pressure Cooker Bone Gravy

A pressure cooker runs at around 115C, well above the boiling point of water, and that speeds collagen conversion up dramatically. You will not quite match a long slow stock for clarity, but for a weeknight you get eighty per cent of the result in a fifth of the time. Roast the bones first, that part cannot be short cut.

Ingredients

Makes about 600ml

• 1.5kg (3lb 5oz) beef bones marrow, knuckle and rib, cut small enough to fit
• 1 tbsp beef dripping
• 1 large onion quartered
• 1 carrot
• 1 stick celery
• 1 tbsp tomato purée
• 1.8 litres (3 pints) cold water or up to the maximum fill line
• 1 bay leaf
• 2 sprigs thyme
• 25g (1oz) butter
• 25g (1oz) plain flour
• 1 tsp Worcestershire sauce
• salt and black pepper

Kit

• Roasting tin
• Pressure cooker or multicooker
• Fine sieve
• Wide pan

Method

1. Heat the oven to 220C fan (240C conventional, gas 9). Rub the bones with the dripping and roast for 45 minutes, adding the onion, carrot, celery and tomato purée for the last 15. The pressure cooker cannot brown anything for you, so all the colour has to come from this stage.

2. Load the bones and vegetables into the pressure cooker. Deglaze the roasting tin with a mug of water on the hob and pour that in too.

3. Add cold water to cover the bones, but never above the maximum fill line, which is usually two thirds. Overfilling a pressure cooker with a liquid that foams is genuinely dangerous.

4. Add the bay and thyme, lock the lid and bring up to high pressure. Once it is up, cook for 90 minutes. That is roughly equivalent to six hours of open simmering for collagen breakdown.

5. Let the pressure drop naturally rather than venting it fast. A quick release makes the liquid boil violently inside the pot, which clouds the stock and can spit through the valve.

6. Strain through a fine sieve. Because you could not skim during cooking, this stock will be cloudier than a hob one, which is a fair trade for the time saved. Chill briefly and lift the fat off.

7. Reduce the stock in a wide pan from around 1.4 litres to 800ml, about 15 minutes, which also drives off any pressure cooker flatness.

8. Make a roux with the butter and flour, cook it for 2 minutes to pale gold, whisk in the hot stock and simmer for 5 minutes. Add the Worcestershire sauce, season and serve.

Tips worth knowing

• Natural pressure release, every time. Venting fast is the single biggest cause of murky pressure cooker stock.
• Cut the bones smaller than you would for a hob stock. More surface area matters even more when the cook time is short.
• You cannot skim under pressure, so the roasted bones going in clean helps. Give them a quick rinse of the burnt bits before they go in the pot.
• The reduction at the end is not optional. Pressure cooked stock always tastes slightly muted and boiling it down for a quarter of an hour sharpens it right up.

Keeping and reheating

Stock keeps four days chilled and four months frozen. Finished gravy keeps three days and reheats well with a splash of water.

Questions people ask