If you plan to roast your bones, preheat the oven at 200/180 (fan). Distribute the bones evenly across one or two roasting tins.

Roast the bones for no more than 30 minutes. You want the outside of the bones to be browned but you don't want the bones to be fully roasted throughout as you want the marrow to be kept intact prior to cooking in water.

Place the chopped vegetables in the slow cooker/large saucepan.

Scatter the herbs, seasoning and apple cider vinegar and place the raw or roasted bones into the pan. Try to ensure the bones are not sticking out higher than the lip of the pan so a lid can fit on comfortably.

Top up the pan with water. Try to ensure the contents are just covered with water. So I estimate around 1-1.5 litres should do it.

Turn up the heat until the broth is boiling. Let it boil for around 5 minutes.

Turn the heat down to the lowest setting. On a slow cooker this is easy, but on a hob I'd select the smallest burner/hob ring and turn the heat way down so it's barely simmering.

Put the lid on and leave it. Check after 3 hours initially to see how much the liquid is reducing.

Every few hours and before straining use a slotted spoon to skim any scum from the top.

For Fish broth, 6-8 hours should suffice, Chicken 12-24 hours, Beef 24-48 hours.

Once ready, find a large, clean vessel to strain the broth into. Use a fine mesh strainer pour the broth into the vessel and allow to cool for around an hour.

There will be a layer of fat on the top, and depending on the meat and type of bone, the fat content will vary.

Make sure the vessel is suitable for fridge/freezer storage. The broth will last up to 6 months in the freezer or 7 days in the fridge.