Cabbage and Spinach Pie

Ingredients:

3 eggs
250 ml of full-fat kefir
80 g of butter
2 to 2.5 cups of flour
1 tsp of baking powder
Salt

Filling:
1 small head of cabbage
2 bunches of spinach
Salt
Pepper
Green onions/garlic

Before preparing the dough, finely chop the cabbage and slice the spinach.
Mix them together, add the onions and garlic, and season with salt.
For the dough: whisk the eggs with salt, then add the kefir and melted butter.
Stir in the flour and baking powder.
Grease a 20×30 cm (approximately 8×12 inches) baking dish with butter, spread half of the dough (it should be thick like sour cream) in the dish, layer the filling on top, and then add the remaining dough.
Bake at 180°C (about 350°F) with convection for 30 to 40 minutes.