Mix together all of the ingredients in a saucepan.
Bring to a slow rolling boil. Turn the heat down to medium-low and allow to simmer, stirring often, for about 3 hours (it should reduce and thicken).
Once complete, remove and discard the bay leaf. If resulting ketchup is too "lumpy" for your taste, press it through a fine mesh sieve to remove the lumps.
Store ketchup in an airtight container in the fridge.