2 cups flour
1/2 tsp salt
1/2 tsp baking soda
1 cup buttermilk (1 cup milk mixed with 1 tbsp lemon juice let stand 10min)
Mix together flour, salt, soda. Make a well and slowly incorporate the buttermilk. You may have to use your hands.
Turn out onto a floured surface and make into a round loaf - use a knife to make an X on the top. Place in a cast iron skillet or dutch oven and put it in a preheated oven at 450º.
Bake for 10 minutes and then reduce the heat to 400º and bake for 20 minutes.
Remove and let cool on a rack.