Ingredients

• 500 g filo pastry sheets (kori)
• 400 g Bulgarian sirene white brined cheese
• 5 eggs
• 400 g Bulgarian yogurt (kiselo mlyako)
• ½ tsp baking soda
• 120 g butter
• 2 tbsp sunflower oil
• 2 tbsp water

Method

1. 01
   Heat the oven Heat the oven to two hundred degrees Celsius, then melt the butter and stir in the sunflower oil.
2. 02
   Activate the soda Stir the baking soda into the yogurt, keeping back two tablespoons of yogurt for the topping, and leave it for about five minutes until it looks foamy and has grown a little.
3. 03
   Make the filling Beat four of the eggs in a large bowl, then mix in the foamy yogurt and the crumbled sirene until evenly combined.
4. 04
   Grease the tin Brush a baking tin about twenty five by thirty five centimetres with butter and lay two sheets of filo in the bottom, brushing them with the butter and oil mixture.
5. 05
   Layer the pastry Spread a few spoonfuls of filling over the sheets, then lay two more sheets on top, brush with butter, and keep repeating until the filling is used up.
6. 06
   Finish the top Cover with the last two sheets, brush them well with butter, and cut the banitsa into squares with a sharp knife, going right down to the bottom.
7. 07
   Add the topping Beat the last egg with the two tablespoons of yogurt you kept back and brush or pour it evenly over the top.
8. 08
   Bake the banitsa Bake on the middle shelf for about forty minutes, until the top is deep golden and puffed and the filling is set.
9. 09
   Rest under a towel Sprinkle the hot banitsa lightly with the water, cover it with a clean kitchen towel, and let it rest for about ten minutes before serving.