Chapati

somehow I never manage to make chapatti. Most of the time it is chewy. I knead the dough well, use 200gr flour+150ml water. Cook it on med. high heat in cast-iron pan well heated each side for 2-3 min. Most of the time it forms "bubbles. When done I wrap the chapatti in a kitchen towel.

Any ideas, suggestion are greatly appreciated.
Suz.