If you are using leftover lamb bones, you don't have to roast them and can add them straight to a large stock pot.
If you are using fresh bones, preheat the oven to 425F/200C. Rub them with olive oil and place the lamb bones onto a baking sheet or roasting tray. Roast for 45 minutes until browned, turn them halfway. Add the roasted lamb bones and juices to a large stock pot.
1 1/2 lbs lamb bones, 1 tbsp olive oil
Wash and roughly chop the carrot, onion, and celery and add them to a large pot. You don't need to peel the onion as it gives the broth extra color.
1 carrot, 1 onion, 1 stalk of celery
Add the herbs, garlic cloves, a bay leaf, peppercorns, and 1 tbsp of apple cider vinegar.
2 cloves garlic, 1 bay leaf, 1 tsp dried rosemary, 2 tsp dried thyme, 5 black peppercorns, 1 tbsp apple cider vinegar
Top up the stock pot with 8 cups of filtered water. Check the water level and add more water if the bones and vegetables are not fully covered.
8 cups filtered water
Bring everything to a boil and reduce the heat. Simmer the stock and skim off any foam on the surface during this time. Cook the mixture for 3 hours to make lamb stock and at least 10 hours to make lamb bone broth. Adding extra water if needed.
Strain the lamb stock through a sieve into a freezer and heat-proof containers. Skim off the fat at the top. Once fully cooled, store in the fridge or freezer.
Lamb stock or bone broth in the slow cooker
Follow the instructions above and add all ingredients to your slow cooker.
Cook on low for 12 hours to make bone broth and 8 hours to make stock.
Lamb stock or bone broth in the pressure cooker (Instant Pot)
Follow the instructions above and add all ingredients to your pressure cooker.
Choose high pressure function and cook on high for 4 hrs to make lamb bone broth. Choose the broth function to make stock.
Bone broth: Min. 10 hrs stove, 12 hours slow cooker, 4 hours pressure cooker.
Storage: Pour the broth through a fine sieve into heat and freezer-proof, airtight containers or ice cube trays while warm. Once fully cooled, you can easily remove the fat at the top and store the stock in the fridge or freezer. Bone broth can be stored up to one week in the fridge and three months in the freezer.