Boil the kettle. Sift flour. Make a dough for plachind with boiling water. To do this, mix flour, oil, salt. Pour boiling water in a thin stream, stirring constantly so that there are no lumps. Knead the dough. Leave the lean custard dough under a towel for 20 minutes.
At this time, make the filling. Peel and wash potatoes and onions. Grate raw potatoes on a coarse grater. Chop the onion. Place the onions and potatoes in a bowl. Season with salt and pepper. Mix all.
Divide the dough into 4-6 pieces. Roll out the dough thinly. Make 8 cuts on the circle (you get something in the form of a chamomile with petals), put the potato filling in the middle and wrap them through the petal in the middle (close the filling with them).
Preheat a frying pan, pour 30 g of vegetable oil. Put plachinda in a skillet with heated oil and fry on both sides (5-6 minutes) over medium heat, covered, until golden brown.
So fry all the plachindas ready to put in a pile. Serve the placindas with warm potatoes.