Mix the water and flour together to make a thin paste. Combine with all of the remaining ingredients in a food processor, and process until blended and smooth. This should only take 30-45 seconds. It really depends on the texture you like.
Once you are happy with the mixture, divide it between three ungreased 7x4" pate moulds (or loaf tins). (If using the pate moulds, you will get 3 moulds out of the mixture. If you use either smaller or larger tins you will need to adjust the cooking time accordingly.) Cover them with foil.
Place the three small loaf tins in a large baking dish. Place in the preheated oven and fill the baking dish with hot water from the kettle so that the water goes halfway up the sides of the loaf tins.
Bake first for 25 minutes, then take off the foil and bake for another 25 minutes. Remove tins and cool. Once cooled, cover with cling film and store in the fridge for up to 5 days.
Instead of baking all three tins at once, you can freeze one or two tins before baking. Then defrost at room temperature and then bake as directed!