Stir together salt, baking soda and flour. Then pour in buttermilk and stir a few times, just until flour is incorporated and it is too hard to stir anymore.
Very lightly flour a cutting board and put dough on, knead 8 times with heels of your palms. Make into a ball.
Put a piece of parchment paper on a cookie sheet and place ball dough in middle.
Use a knife to cut an x in the middle of the dough.
Bake at 430 for 18 minutes, then turn down to 390 degrees F for an additional 20 minutes or until knife comes out clean when placed into the center of the loaf and sounds hollow when knocked on the bottom of the loaf.