Simmer the prunes in water to cover
until soft, or soak overnight. Drain, reserving 60ml of the soaking
liquid. Stone and chop the prunes.
Combine the yeast and the reserved
prune liquid, stir and leave for 15 minutes to dissolve.
In a large bowl, stir together the
flours, bicarbonate of soda, salt and pepper. Make a well in the centre.
Add the prunes, butter and buttermilk.
Pour in the yeast mixture. With a wooden spoon, stir from the centre,
folding in more flour with each turn, to obtain a rough dough.
Transfer to a floured surface and
knead until smooth and elastic. Return to the bowl, cover with a plastic
bag and leave to rise in a warm place until doubled in volume, for about
1 1/2 hours.
Grease a baking sheet.
Punch down the dough with your fist,
then knead in the walnuts. Shape the dough into a long, cylindrical
loaf. Place on the baking sheet, cover loosely, and leave to rise in a
warm place for 45 minutes.
Preheat the oven to 220oC/425oF/Gas
With a sharp knife, score the top.
Brush with milk and bake for 15 minutes. Lower to 190oC/375oF/Gas
5 and bake for 35 minutes more, until the bottom sounds hollow. Cool.