Take a large frying pan and place on high heat. Add the butter and the oil and when the butter melts add the lamb cubes searing all sides. Towards the end add the fresh onions to soften a bit.
Add the garlic and cook for just 30’’ and until fragrant. Add the rice, stir to get well coated and pour the wine along with the water while stirring frequently. When most of the liquid has been absorbed by the rice season with 1 tsp of salt and pepper. Remove from the heat and add them in an oven proof deep dish and keep aside.
In the meantime, turn the oven on, air circulation to 180°C, rack set in the middle.
In a glass bowl add the eggs beating them well while in another bowl add the yoghurt and the flour. Whisk them well and add the beaten eggs along with the mint while seasoning them with the remaining ½ tsp of salt.
Go back to the dish with the meat and spread on top the yoghurt mixture. Place in the oven and cook for 40’ until lightly golden brown. Then remove from the oven and grate the kefalotyri. Return to the oven and cook for 10’ more.
Remove from the oven and allow to cool and set for about 20’. Then serve large spoonful’s into individual plates next to a green’s salad.