Bring a small pot of water to boil. Add 50-60g brown (toasted) buckwheat and cook as it says on the packaging, when cooked, cover with lid and let steam until nice and a bit fluffy.

For the topping, toast the green buckwheat groats in a dry pan over medium heat for 10-15 minutes, shaking frequently, until just slightly darkened.

In a large bowl, add water and starter and mix well until the starter dissolves and looks milky. Then add the bread flour and salt. Mix with your hands or a sourdough whisk until shaggy and rough. Cover and let rest for 30-45 minutes.

Add the cooled, cooked buckwheat and perform the first set of stretch and folds. Try distributing the buckwheat evenly. Then perform 2 more sets of stretch and folds every 35-45 mins.

When the last set is done cover the bowl and let the dough ferment at room temperature for 3-4 hours.

Turn the dough out onto a lightly floured surface. Shape the dough as you would a regular sourdough loaf, pull the edges toward the center, and roll it into the log form.

Place the shaped dough in the banneton and stitch the dough after 15 mins. Cover with a plastic bag with rubber band and place in the fridge overnight.

The next morning, remove the dough from the fridge, flip it on the floured surface. Use a sharp knife or bench scraper to divide it into 6 equal portions.

Place the cut buns on a parchment-lined baking sheet, spacing them about 5cm apart. Brush or spray the tops lightly with water and sprinkle generously with the toasted green buckwheat.

If you want you can score each bun with a simple slash or cross on top. Place a small baking dish on the bottom oven rack and fill it with boiling water to create steam.

Bake for 20-25 minutes, until the buns are golden brown and sound hollow when tapped on the bottom. Transfer to a wire rack and let cool for at least 15 minutes before slicing.