In a large bowl mix in the two types of flour, sprinkle the salt and form a well in the middle but try and sprinkle no salt in the actual well as yeast and salt don't like each other.
In a cup/mug mix the yeast with the sugar and pour 100 ml lukewarm water. Mix well until both sugar and yeast dissolve. You could leave it in the cup or pour it in the well formed in the flour. I recommend the latter as leaving it in the cup requires that you keep an eye on it as it may overflow so, best is to pour it in and set aside for around 20 minutes.
Once the yeast has become all a big bubble start kneading the bread. Pour the remainder of the water and the buttermilk. Mix very well and knead until the dough no longer sticks to your hand. This will probably take 4-5 min or so of continuous kneading.
Gradually add the olive oil while still kneading. Feel free with punching, slapping, stretching, whatever you feel like doing with it but as I said the low glutenous flours do not require that much working/kneading.
When finished, smooth the surface into a big ball and cover. Allow to proving for as many hours as you fancy. I normally leave it between 2-4 hrs. You may need to push back the dough once in between and allow to rise again.
When finished with proving just form the dough into the buns and place onto a greased dish. Allow to prove again for an extra 40-60min and then place in the oven. Bake at 190C or 375F for 40-50 min until they get to a nice golden colour.
When ready, turn off the oven, take out and allow it to cook for a good 10-15 minutes. Then, take out from the dish and place on a cooling rack. If you leave it too long in the baking dish it will sweat so it needs to be taken out as soon as 10-15 min after taking it out of the oven. This is an important step.