How to make
Wash the tomatoes, cut them into cubes and blend them in a blender or food processor.
Pour the blended tomatoes into a large pot and leave them to boil, until they are reduced by a third.
Add salt, vinegar, sugar, oregano, starch and the preservative. Leave the mixture to boil a little more, until it starts to thicken.
Pour the homemade ketchup, while it is still hot, in small jars. Close them tightly and turn them upside down. Leave them to cool.
Store the delicious homemade ketchup in a cool and dark place.