How to cook
All products need to be at room temperature. The milk needs to be slightly warm but not hot.
Pour the milk in a bowl, dissolve the yeast in it, add the sugar and stir. Leave it for 10 min. to bubble.
In another bowl, beat 1 egg + the yolk of the other. Set the remaining egg white aside for smearing at the end. To them add the yoghurt and oil.
Sift the flour in a large container, salt it, make a well in the middle and pour in the egg mixture. Start kneading, while slowly adding a bit of the milk with yeast at a time. Stir until all of the ingredients are absorbed and you get a sticky doughy ball. Sprinkle a little flour on your countertop or table.
Pour the mixture onto the counter and start kneading energetically. If needed, add a little more flour, knead until you get a dough ball that doesn't stick to your hands. The dough needs to be smooth, soft and stretchy.
Cover the dough with foil or a towel and leave in a warm area to rise for 1 hour. Divide up the risen dough into 4 equal parts, shape each one into a ball and cover, leave them for another 10 min.
Sprinkle the flour with a little flour, take 1 ball and roll it out into a thin, round, large sheet. Crumble the feta cheese into a plate.
Divide it up into 4 parts, so you have enough for each sheet. Smear the rolled out sheet with butter, sprinkle with the feta and fold it up like a letter. Leave it aside.
Repeat with the next dough ball but before you fold it, place the 1st folded sheet in its middle. Take the opposite ends of the sheet and fold them in toward the sheet in the middle, covering them. Set it aside.
Repeat this process for the remaining 2 dough balls, while placing the set aside bundle in the middle before you fold them up. You need to get a thick sheet of dough, similar to a letter envelope, at the end.
Flip it with the folded part facing down and carefully roll it out to the diameter of the round form you intend to bake in, using a rolling pin.
I don't recommend it being a large diameter. Use 11 3/4″ (30 cm) max diameter form with high walls, to allow the tutmanik to swell properly.
Smear your form with a little butter, use baking paper if you prefer. Transfer the dough carefully into the form. Cut it into 8 triangles on top using a sharp knife, as if cutting a cake. Make deep cuts without reaching the bottom.
Cover it and leave it for 30 min. to rise and double in volume again. Heat the oven to 338°F (170 °C). Smear the tutmanik with the egg white but be careful not to smear into the cuts because they'll stick together during baking. You can smear with egg yolk too if you like.
Sprinkle on seeds of your choice, I used linseed.
Put the form in the oven and bake 30-40 min. while keeping an eye on it. If it starts to blacken on top, cover with a sheet of aluminum foil.
Take the baked tutmanik out and leave it to cool a bit on a cooking grid. It becomes as soft as cotton, with a fluffy crust, lots of feta and a buttery aroma.
Source: Elena Nedelkova.