Ingredients
3 cups All-Purpose Flour
1-3/4 teaspoons Kosher Salt (or 1-1/2 teaspoons Table Salt)
1-1/8 teaspoons Baking Soda (no more)
2-1/4 cups Buttermilk

Directions
Preheat oven to 450F. 
Whisk together Flour, Salt and Baking Soda.
Add Buttermilk.  Mix well.
Scoop dough into Dutch Oven or heavy lidded cast iron pot.
Cut X  in top of dough.  This will help bread cook in center.
Put lid on and place in oven and cook to internal temperature of 205F (approx. 40 minutes).
Remove from oven, remove from pot, let cool a bit.
Enjoy!

NOTE: In the video I used milk with vinegar instead of buttermilk.  I tried the same recipe with the suggested buttermilk and it worked much better.