Preheat oven to 400°F (204°C).
In a large bowl, mix flour, salt, and baking soda together.
Make a well in the center of the flour mixture and add buttermilk.
Mix the ingredients gently with an open hand until the mixture comes together. (See video.) Do not over mix.
Remove the dough from the bowl and place it on a floured surface.
With a few turns, shape the dough into a round.
Transfer the dough to the baking sheet (or another piece of equipment being used for baking bread).
Flatten dough to 1 1/2 inches.
Take a sharp knife and make a cross on top of the flattened dough.
Next, use the tip of the knife to make four small indentations on top of each quarter of the dough. (See video.)
Add a small bit of water to the measuring cup that held the buttermilk and brush this mixture across the top of the dough.
Transfer the baking sheet with the dough to the middle rack of the preheated oven.
Bake for 30 minutes or until golden brown on top and a toothpick inserted in the center of the bread comes out clean.
Transfer bread to a cooling rack and allow to cool before slicing.