Roti (also called chapati) is the daily bread of Indian home cooking: just whole wheat flour, water, and salt, with an optional teaspoon of oil for tenderness. Traditionally made with atta — a finely milled durum or hard wheat flour. Regular whole wheat flour from a North American grocery store works; the result is slightly thicker but identical in spirit. The technique that makes roti puff into a balloon is a final pass directly over an open flame — the trapped steam blows the layers apart. A hot dry skillet works too if you don't have a gas stove.