Sieve flour with salt, baking powder and soda. Heat diluted milk till it is luke warm(tepid). Sprinkle yeast in milk and mix and mix with a spoon. Cover with a lid and keep in warm place for 10 minutes. Take sieved flour in a broad basin and make a den in the centre. Pour yeast mixture in that. Leave for a minute and gather dough with hands. Sprinkle warm water if necessary, for mixing the dough. Keep the dough closed so that there is enough space for the dough to raise. Leave aside for 2 to 3 hours. Make even sized balls. Roll chapatis thicker than normal chapatis. Sprinkle little water on top of chapati and spread with hand. Heat an aluminium pan with handle. Put chapathi on the pan, so that water applied side sticks to the pan. Close top with a lid. Heat in medium flame till roti puffs up. Turn the pan upside down with the handle so that other side of chapati is heated on direct flame. Carefully loosen with a flat laddle and remove from fire. Serve hot.