In a bowl take 100 ml lukewarm water. Dissolve yeast and sugar in it. Let it rest until it froths.
In another kneading bowl take flour, milk powder, salt and activated yeast solution. Start kneading the dough.
Take the dough out on the counter and add oil to it. Knead it for 5 minutes.
Keep the kneading dough in a greased bowl and cover it to avoid crust formation. Keep the bowl in any dry and warm place until dough doubles in volume.
Meanwhile, in a pan heat oil. Add onion and chili and saute for 2 minutes. Now add grated cottage cheese and all the dry spice. Cook the stuffing for another 2 minutes. Switch off the flame and transfer the stuffing to a bowl.
Punch the fermented dough to release the air. Divide the dough into 6 equal portions.
Roll each dough ball into circular disc. Put stuffing on it. Fold all the corners towards centre and seal properly.
Using a rolling pin, roll these tuffed balls again.
Let them rest on counter for 15 minutes. Meanwhile preheat the oven at 200 °C.
Place all the kulchas on a greased baking tray and brush with milk. Sprinkle sesame seeds.
Bake these kulchas at 200 °C for 15 minutes in a preheated oven.
After baking, transfer the kulchas on cooling rack and brush with butter immediately.