Place the water and all the other ingredients up to and including the lemon zest in a pan, bring to the boil and then reduce the heat. Add the flour all at once, stir with a wooden spoon for approx. 2 mins. until a smooth dough is formed which separates from the base of the pan. Remove the pan from the heat. Using the dough hook on a hand mixer, gradually stir in the eggs; the dough should be soft but not runny.