Melt the butter with the olive oil. Crumble the feta cheese. Smear each phyllo pastry sheet generously with the butter mixture and put crumbled feta cheese every 5 sheets. Place in a buttered oven dish. Continue until out of sheets. Smear generously with the rest of the butter mixture on top and cut it into pieces.
Beat the eggs with a whisk and while stirring nonstop, pour in the hot water in a thin trickle. Stir vigorously so the eggs don't boil. Pour this over the phyllo pastry and let it sit for 15 min. until the liquid is absorbed.
Bake at 356°F (180 °C) with the fan on for about 25-30 min. or until it reddens well.