If cooking beetroot from scratch, start here:
Set your oven temperature to 200 degrees C (400F) to warm up.
Wash the beetroots and let them drain.
Without cutting or peeling, place the beetroot in the foil and drizzle with oil. Wrap the beets in the foil parcel with the seam to the top and place this parcel into your oven tray. Let the beetroot bake for around 50min, then open the top of the foil parcel for a further 10 min for a light roasting and deepening of the flavour.
Take the beetroots from the oven and test if they are done by stabbing them with a sharp knife. If the knife passes through an individual beetroot easily, it is cooked. If not, continue to cook in the oven until you are satisfied that they are done.
When done, set the cooked beetroots aside to cool.
If using pre-cooked beetroot, start here:
While the beetroot is cooling wash, clean and finely chop up the carrot, onion and celery, garlic and ginger.
Add the oil to your pan, and heat up, then add the chopped vegetables. Let them slowly soften.
Add the garlic, ginger, chilli flakes and salt and stir into the vegetable mixture and cook on low heat.
Once the beetroot is cool enough to handle, peel and trim them, then chop them into small pieces.
Add the beetroot and the vinegar to the softened spiced vegetables, stir and bring up to a simmering point where you keep it for 20 minutes. Check and stir from time to time. Then set aside to cool for 10 minutes. Make sure that you cool it enough as you want to avoid any pressure build-up from hot ingredients in a blender!!
Once cooled, add the vegetables to a clean blender and blend for 3 minutes on the highest setting making sure the mixture becomes smooth. (while you can use a stick blender in the pan, I have found that the I, the wall, cupboards, and anything else in the vicinity end up being tattooed in beetroot sauce all too easily!).
At this stage, you can opt to pass it through a fine sieve if you want, although I just move straight on myself.
Pour the blended mixture back into your pan, and slowly heat up again. Add the sugar and stir well, making sure that the sugar is fully incorporated. Once it starts to boil, turn the heat down to simmer. Now decide again whether the consistency is to your liking and review the tips above as needed.
After 10 minutes, take the pan off the heat and set it aside while lining up your sterilised jars and/or bottles. Use the funnel(s) to pour or ladle the sauce into the jars/bottles and seal them.
Let these cool completely for 24 hours and at room temperature.
Label and date the containers. Check that they are sealed well.
Keep the ketchup in a cool, dark place for up to 3-6 months. Once opened, store in the fridge for up to 2-3 weeks (if it lasts that long!).