In a large bowl, mix the flour, oil and salt with ¾ cup lukewarm water. Knead directly in the bowl until smooth, about 5 minutes. If the dough starts to feel dry, add more water as needed, ½ tablespoon at a time. Divide the dough into 12 even balls, placing each ball back in the bowl. Cover the bowl loosely with plastic wrap. Let rest in a warm place for at least 30 minutes or up to 1 hour. The dough should be soft and spongy.
Lightly dust your work surface with flour and pat a ball into a thick disk. Use a rolling pin to evenly roll it into a thin, 5-inch-wide disk, flipping and flouring as needed.
Heat a large cast-iron skillet over medium-high. Put the disk in the hot pan. When bubbles start to form and the roti starts to turn white, about 30 seconds, flip it over to cook the other side. It should be puffy in places and freckled brown. If you want to fully puff the roti, use tongs to gently place it directly on a low gas flame for about 2-3 seconds, then quickly remove it. Use the back of a spoon to lightly coat one side of the roti with ghee, if you like, or leave plain, then tuck into a clean dishcloth to keep warm. Repeat with the remaining dough.