In a medium bowl whisk together the flour, salt and baking soda, make a well in the middle and add the lard or olive oil, mix with a fork, then slowly add the milk and mix.
When almost combined move to a flat surface and knead into a smooth ball. Place in a lightly oiled bowl, cover with plastic and let rest 20 minutes.
Divide dough into 4 balls, sprinkle a wooden board or flat surface with a little flour and place balls on top, cover with a tea towel and let rest 20 minutes. Roll out each ball to approximately 8-10 inches (20-25 cm)and very thin, almost paper thin. Prick the dough with a fork.
Brush bottom of medium size frying pan with a little olive oil, heat on medium heat until hot, when hot place one Piadina at a time on the pan, and flip when golden, flip each side two times.
Immediately fill cooked warm flat breads with desired fillings. Eat warm. Enjoy!
** Recipe can be doubled.
Notes
If you wish you can use some whole wheat flour, I recommend not using more than 30% of the all purpose flour. In other words 75 grams / 1/2 cup + 1 1/2 tablespoons whole wheat flour and the remaining will be all purpose flour.You can add fresh herbs to the dough, such as finely chopped fresh rosemary, oregano, thyme or even fresh parsley would work well. I would whisk it in with the flour. You could even add a little garlic or garlic powder for flavor.To store the flatbread, wrap them in plastic wrap and store at room temperature. They will keep for up to 2 days at room temperature. If stored in the fridge they will last 4-5 days. Re-heat for a minute or two before serving. The can also be frozen, wrap them well in plastic wrap then place in a freezer bag. They will keep for up to 4 months in the freezer.