Whisk water and chakki atta in medium bowl until no lumps remain. Microwave, whisking every 30 seconds, until mixture thickens to very stiff, gelatinous consistency that does not flow, about 2 minutes.

Add chakki atta, water, and oil to flour paste and mix with rubber spatula until all flour is moistened (if dough is too stiff for spatula, let cool slightly and knead by hand). Cover and let rest for at least 30 minutes or up to 1 hour.

Sprinkle salt over dough and knead in with your lightly oiled hand. Transfer dough to lightly oiled work surface and knead until mostly smooth, about 1 minute. Divide into 12 equal portions. Flatten 1 portion to ½-inch thickness with palm of your hand. Fold edges toward center to form ball. Turn ball seam side down and round to form smooth sphere. Repeat with remaining portions.

Coat balls very lightly with oil. Press each to form 2-inch disk. Heat 10-inch carbon-steel or cast-iron skillet over medium-low heat. Place all-purpose flour in shallow bowl. Line rimmed baking sheet with parchment paper. Line plate or shallow bowl with clean towel. Roll second clean towel in tight wad.

Dip 1 disk in flour and turn to coat. Roll gently to 6-inch round of even thickness (it needn't be perfectly round). Transfer to prepared baking sheet and cover with second piece of parchment. Roll out 2 more dough balls, placing rolled rotis under parchment, 3 rotis per layer, and overlapping as little as possible. Increase heat under skillet to medium-high, and continue rolling and covering remaining dough balls, separating each layer of 3 rotis with parchment.

Gently place 1 roti in skillet. Cook until small bubbles begin to form on surface and underside of roti is light blond with a few darker spots, 15 to 20 seconds. Using metal spatula, flip roti. Cook until underside is speckled evenly with brown spots, 40 to 60 seconds (if roti colors too quickly or slowly, adjust heat accordingly).

Flip roti. Press edges gently with wadded towel, rotating roti as you press, until roti puffs. Cook puffed roti for 10 seconds longer, then transfer to prepared plate (roti will deflate). Brush lightly with ghee or butter, if using. Cover with towel. Repeat cooking remaining roti. (Roti are best eaten fresh but can be stored at room temperature for up to 2 days. Warm briefly in skillet before serving.)