Makes 2.6l/4½ pints/11¼ cups
1.6kg/3½lb mixed beef bones: shin, rib or sawn marrow bones
2 tbsp oil
3 streaky bacon rashers (slices), chopped
2 onions, roughly chopped
2 carrots, sliced
3 celery sticks, sliced
3 fresh thyme sprigs
2 bay leaves
½ tsp salt
½ tsp black peppercorns
1 Preheat the oven to 190°C/375°F/Gas 5. Put the bones in a roasting pan, drizzle with 1 tbsp oil and cook for 45 minutes or until browned.
2 Heat the remaining oil in a large pan over a low heat, add the bacon and onions and cook gently for 10 minutes or until the onions are tender and golden.
3 Add the carrots, celery, herbs, salt and pepper and browned bones with 2.8 litres/5 pints/12½ cups cold water, or enough to cover the bones by about 5cm/2in. Bring slowly to the boil over a low heat. Skim off any foamy scum with a slotted spoon, then partially cover the pan and simmer gently for 3 hours.
4 Strain through a fine sieve into a bowl. Set aside to cool, then skim off the fat. Store in the refrigerator for up to three days.