Combine the flours and salt in a large bowl. Cut in the butter and mix until the texture is crumbly. Stir in the water and mix lightly until the dough will gather into a ball.

Knead the dough on a lightly floured surface, until smooth and elastic, about 5 minutes. Cover the ball of dough and let it rest in a warm place for at least 30 minutes, and up to 2 hours.

Divide the dough into 12 portions. Roll each into a ball between the palms of your hands. On a lightly floured surface, roll out each ball into a thin round about 8in, 200mm in diameter, layering between sheets plastic wrap.

Heat a heavy skillet, griddle or iron frying pan over high heat until it begins to smoke. Place a tortilla in the pan and cook for 30 seconds, pressing down with a metal spatula as it begins to puff up. Turn and cook the other side until speckled and brown, but still soft enough to fold - about 30 seconds. Remove and cook the remaining tortillas the same way.

Serve at once or wrap in plastic when cool and refrigerate for up to 3 days.

Mexican Cooking. Wise, Victoria. Lansdowne Publishing Ltd
Foods of the World series. 1993