Take the yeast in a cup; add the sugar and warm water. Cover with lid. After 10 minutes you will see all frothy texture on the top, don’t disturb. Keep it aside. This shows that yeast is still active.
In a wide bowl, take the flour, add the yeast mix. Then add the salt. butter and curds. Crumble well. Slowly knead to soft pliable dough using water as required. Punch it well for couple of minutes.
Cover with a wet muslin cloth and keep it in a warm place for 1 - 2 hrs. Once done, remove the cover, punch it down again. For making on tawa you need not wait for 2 hrs, the dough gets ready by 30 - 40 mins max.
When you are ready to make, get the tawa on stove.
Divide the dough into small balls, dust it in flour. Roll them into oval shapes.
Make couple of them all rolled out by the time the tawa gets heated up.
Place the rolled out Naan on the tawa. Cook on high flame. You will see the Naan puffing up. Gently flip to the other side. The Naan puffs up on both sides.
Remove and quickly apply butter over the top.
It is enough to cook on the tawa for the naan to be done well. If you want those classic black spots on the top, you can put the cooked naans on direct flame using a tong. This way your naan will have those traditional brown/ black spots on top.