The Liquid Levain
Whisk together the ingredients for the first preparation in a bowl, cover with plastic wrap and leave to ferment for a day at room temperature. Whisk together the second preparation ingredients in the same way, add it to the first preparation and mix again. Cover with plastic wrap and let it ferment for another day. Whisk together the third preparation ingredients as for the others, add it to the levain and mix again. Cover with plastic wrap and let it ferment for half a day. Your levain is now ready to use.
In a bowl, dissolve the sugar in the water, then add the yeast, one portion of liquid levain and 125 g (4½ oz) flour. Whisk them together and let the mixture ferment for 2–3 minutes. Add the milk powder, butter, salt and another 125 g of the flour and mix well. Continue to add the flour and combine until you have a dough that holds together well and comes away from the bowl. Tip the dough onto your work surface and knead for about 8 minutes until it is quite smooth but not too stiff. Add a little flour if necessary. Scrape out your mixing bowl, then lightly oil it with a little vegetable oil and place the dough inside. Cover with plastic wrap and allow it to rise at room temperature for about 2 hours until it has doubled in size.
Shaping the Dough
When the dough has doubled in size, punch it down to release the air and turn it out onto a floured work surface. Let it rest for a few minutes, then divide it into two pieces. Roll out each piece to a thickness of 1.5 cm (⅝ inch) and cut out circles using a 9 cm (3½ inch) round cutter. Dust two or three baking trays with semolina flour and place the circles of dough on top. Scatter over some more semolina flour, cover with plastic wrap and allow them to rise for about 1 hour.
Preheat the oven to 180°C (350°F/Gas 4). Heat a frying pan over medium heat and carefully transfer three or four muffins to the pan, depending on the size of your pan (don’t add too many at once). Cook them for 5–10 minutes on each side until they have a good colour. Finish the cooking in the oven for another 5 minutes to make sure they are cooked right through.