Preheat oven to 450˚F / 232˚C.
In a large mixing bowl, whisk flour, salt, and baking soda to disperse ingredients throughout.
Make a well in the center of the dry ingredients and pour in 1¼ cups of buttermilk. Mix well with a spoon.
Continue to mix using your hands and check the texture. If the dough is too dry, pour in another ¼ cup buttermilk. Continue to knead in the buttermilk and add another ¼ cup more, if needed. You should have a sticky dough; no flour left in the bowl.
At this point, you can add / knead in additional mix-ins.
Prepare a lightly floured surface with a little flour and scoop out the dough.
Knead the dough only a few times to bring the dough together into a nice round shape. Careful not to overwork the dough; no gluten is being developed.
Pat out the dough into 1½ inch thickness.
Score the top of the dough into a criss-cross pattern ("x" shape) using a sharp floured knife. Then using your knife, add about 1-2 inch long slit on the top-center of each quarter to allow for steam to escape and the dough to rise.
Place the round loaf on a cookie sheet lined with parchment paper, in a Dutch oven, or in a skillet.
Bake the bread for 15 minutes at 450˚F / 232˚C.
After 15 minutes, without opening the oven, set the temperature to 400˚F / 204˚C and bake for another 25 minutes.
After 25 minutes, open the oven, turn the bread upside down and bake for another 5 minutes.
Bread is done when the loaf is golden brown, crusty, and sounds hollow when tapped on the underside. A fail-safe method is to check the internal temperature using a thermometer which should read at least 190˚F / 88˚C.
Eat immediately while hot and enjoy!