Cube the butter and place in the freezer for a few minutes to keep cold.
Preheat your oven to 400 degrees. Put a dusting of flour into your dutch oven and shake with the lid on.
In a large mixing bowl, combine all the dry ingredients.
Remove the butter from the freezer. With your fingers work the butter into the flour until it resembled a coarse cornmeal.
Make a well in the center and add the buttermilk. Fold the dough until the buttermilk is fully Incorporated. Dough will be sticky.
Turn the dough onto a floured work surface. Fold the dough instead of kneading until you can form it into a round loaf.
With a knife or pair of kitchen shears, make an "X" shape in the top of the dough. Don't go down too deep.
Place the dough into your dutch oven. Put the lid on and into the oven for 40-45 minutes. The loaf should sound hallow when you tap on it. .
Allow to cool with the lid off before removing to a cooling rack. Serve warm.
Notes
The best way to preserve leftover bread is to wrap it in foil and place in the freezer until you are ready to eat. I wouldn't recommend leaving the bread out at room temperature as it will dry out fast.