Step 1

Put the onions, tomatoes, garlic, 50ml vinegar and the water into a large saucepan over a medium heat. Cook for about 40 minutes, stirring occasionally, until the vegetables have reduced to a pulp.

Step 2

Meanwhile, pour the remainder of the vinegar into another saucepan, and add peppercorns, spices, chillies and bay leaves and infuse over a low heat for 10 minutes. Remove and put to one side.

Step 3

Using a hand blender or food processor, whiz the tomato pulp until smooth. Then rub the tomato pulp through a nylon sieve into a clean pan, making sure that you have extracted all of the pulp, leaving behind only the tomato skins and seeds.

Step 4

Strain the infused vinegar into the pan, add the sugar and set over a medium heat. Bring to the boil, stirring occasionally to dissolve the sugar. Reduce to a simmer and cook until thickened and reduced to a thick consistency, about 500ml.

Step 5

Remove from the heat and season to taste. Pour the ketchup into a jug and use a funnel to transfer it into sterilised bottles or jars. Seal immediately and cool completely before labelling and storing.