To make the dough, pile the flours and 1 teaspoon of fine sea salt on a clean surface and make a well in the centre.
Add the yeast and sugar to 650ml of lukewarm water, mix with a fork and leave for a few minutes, then gradually pour into the well.
Using a fork, slowly bring in the flour from the inner edge of the well and mix into the water. Continue to mix, bringing in all the flour.
When the dough comes together and becomes too hard to mix with your fork, dust your hands with flour and begin to pat it into a ball.
Knead the dough, using your left hand to stretch it towards you and, at the same time, your right hand to push it away from you. Repeat this for about 10 minutes, or until you have a smooth, springy, soft dough.
Place the dough in a lightly greased bowl. Cover with a piece of kitchen towel or clingfilm and leave for about 45 minutes, or until doubled in size.
Pick and finely chop the parsley leaves and place in a bowl. Beat in the butter, then peel and finely grate in the garlic.
Season to taste with sea salt and black pepper, then wrap in greaseproof paper and place in the fridge to firm up a little.
Line three baking sheets with greaseproof paper.
Divide the proved dough into quarters, then divide each quarter into four and finally divide each one into roughly 80g pieces. Roll into balls and place on the baking sheets.
Cover with a damp tea towel and allow to prove once more for 20 minutes, or until the pieces are slightly risen and joining together.
Preheat the oven to 180ºC/350ºF/gas 4, then bake for 10 to 12 minutes, or until pale golden. The dough balls are ready when they sound hollow when tapped on the base.
Leave to cool slightly, then serve and let people tear off chunks to dip into, or spread with, the herby butter.