Butter a baking pan 9x12x2 inches and lay 2/3 of pastry sheets, brushing each sheet generously with melted butter.
06The edges of the pastry sheets should come up above the top of the pan.
07Spread milk custard mixture over pastry sheets and turn in the edges of the phyllo over the custard.
08Cover with remaining pastry sheets, buttering each one generously with melted butter once it gets into the baking pan.
09Pour any remaining butter over top.
10Cut through the first 3 pastry sheets (no one will kill you if it's 4! Just use a light touch and a very sharp, pointy knife.) in 3 inch squares and sprinkle pastry with water.
11Bake in a moderate (350°F-180°C) oven for 45 minutes to 1 hour- until golden on top (not golden-brown).
12Allow to cool.
13Boil the sugar, water and lemon juice for 5 minutes.
14Pour lukewarm syrup over the cooled 'Galaktoboureko'.