Preheat oven to fan forced hottest temperature possible (200°C plus) and place rectangular baking tray in to heat up for at least 10 minutes.
Place 40g EVOO, vodka, egg, water, flour, baking powder and salt into TM bowl and blend 40 sec/speed 6.
Scrape down sides of bowl & blend 5 sec/speed 5.
Rest batter while you prepare hot baking tray by brushing with enough extra EVOO to thoroughly coat the tray. (You should be able to see the oil.)
Pour batter onto tray and smooth it into corners of tray.
Crumble feta evenly over the surface and then dot with the butter.
Bake for 20 minutes until golden brown and crunchy. Rotate the baking tray if necessary to get an even finish on the tart.
Pull foliage off rosemary sprigs and garnish the top of the tart.
Cool slightly before cutting into squares and serving with a large leafy salad, and lemon wedges on the side.