Add beetroot, onion and apple to mixer bowl. Chop for 3 sec/speed 6/MC on or until finely chopped but not mush.
Add remaining ingredients, including 400 g or 14.1 oz water, and cook for 45 min/steaming temp/speed 1/MC off. Put the simmering basket over the hole to avoid making a mess of your kitchen.
When the relish is finished cooking, if you prefer a runnier texture add a little more water. Allow to cool completely before putting into sterilised jars. If you use a sterilised jar and clean spoon/knife for serving this should last several weeks in the fridge.