Dissolve yeast and sugar in warm milk and wait for it to become frothy . Sift together flour and salt and add the yeast mixture, curd and oil. Knead into a soft dough, adding more milk or water as required.
Cover with a moist cloth and leave in a warm place for 5 to 6 hours, or till the dough has doubled in size. Knead the dough once again and let it rest for 15 more minutes.
Divide the dough into balls larger than lemons. Roll out a ball into a 5 cm (round) disc on a lightly floured surface. Place a tablespoon of filling onto the centre, and bring together edges of the disc to enclose the filling. Roll it out once more. Repeat with all the balls.
To cook kulchas you can – Either bake the kulcha in an oven at 200C for 8 to 10 minute. ~ Or place the kulcha on a heated tawa/pan. When one side is cooked, flip over and cook the other side. ~ Or apply water on one side of the kulcha. Place the kulcha on a heated tawa/pan, wet side down, and press with a spoon so that it sticks to the pan. Invert the pan over the flame, so that the kulcha is exposed to direct flame and brown spots appear on the surface.