Mix the soda into the milk. Combine the remaining ingredients, including the milk-soda mixture. Mix well, adding flour if the dough seems to stick. Form a ball and place in a plastic bag or a covered bowl and let stand overnight. Cut into three or four sections. One at a time, roll out into a fairly thin round with a rolling pin, using extra flour if the dough sticks. With cookie cutters, such as star, crescent moon, Santa, angel, etc., cut shapes and bake in a 200 °C (400 °F) oven for about 7-10 mins, or until golden brown on the bottom. Cool flat.