a) we didn't have any baking soda, and
2) we didn't have any buttermilk.
What we had was self-raising flour (coarser ground and a different wheat from the US), Greek yogurt and the ability to improvise.
Preheat the oven to 200C (figure this out yourself if you want to use irrational units).
While the oven is heating mix and then kneed gently:
2 cups (more or less) or about 250 grams of self-rising flour
1 tsp salt
100g +- of Greek Yogurt.
This should form a dampish dough. You may need to add some water, or flour, but the dough should hold together and not be sticky.
Put it on a floured baking sheet, and cut a cross in the top. It should look something like this:
After about 1/2 hour in the hot oven, it will look like this:
It will also sound hollow when you tap it. (Much like yeast bread). It goes very well with bitter, sausage and carrots.
This recipe would work as a "damper" bread and bake well in a Dutch oven.