Warm the milk and water together to about 35C/95F. Crumble in the fresh yeast and stir until dissolved.

In a large bowl, mix the flour, sugar and salt. Add the milk mixture and softened butter, then knead by hand or with a stand mixer fitted with a dough hook for 8 to 10 minutes until smooth and elastic.

Shape the dough into a ball, place it in a lightly oiled bowl, cover, and let rise in a warm spot for 90 minutes, until doubled.

Punch down the dough and divide it into two pieces. Roll each into a small baguette-shaped loaf about 20 cm / 8 inches long.

Place the loaves on a lined sheet pan 33 x 46 cm / 13 x 18 inch, cover loosely, and let rise for 30 minutes.

Bake at 180C/350F for 22 to 25 minutes until pale golden and firm to the touch. Cool completely on a wire rack, then wrap and rest at room temperature for at least 8 hours, overnight is best, so the crumb firms up enough to slice cleanly.

Using a serrated bread knife, slice the cooled loaves crosswise into rounds about 4 mm / 1/8 inch thick. Arrange in a single layer on two sheet pans.

Bake at 150C/300F for 20 to 25 minutes, flipping each slice halfway through, until dry and pale golden at the edges.

Turn off the oven and let the biscuits cool inside with the door ajar for 10 minutes, this helps them crisp fully. Transfer to a rack to cool completely before storing in an airtight tin.