Mix all ingredients together (dissolve the cornstarch in a little water). Season to taste, bring to the boil and cook for 5 minutes. Stir it, it sets easily. Pour into a bottle while it is still hot.
The ketchup can also be perfumed with “crema di balsamico”.
You can also use fresh spices, but you have to reduce the amount of water or increase the amount of cornstarch. If you don`t chop them too finely, they give the ketchup a rustic look.