Pour both flours into a large bowl and sprinkle in the salt.
Crush the fennel seeds using a pestle and mortar. This will add texture to the bread by varying the size of the fennel seeds.
Add the yeast to the tepid water and stir, this will wake up the yeast.
Sprinkle the fennel seeds into the flour and slowly pour in the yeasted water and melted butter.
Using your fingertips, work the flour and water together until you have the start of a dough. Once combined tumble the dough out onto a lightly floured board.
Knead the dough for 8-10 minutes and form the dough into a ball.
Place the dough into clean oiled bowl and allow to prove for 1 hour 30 minutes in a warm place away from draughts.
After the first prove, tip your dough out onto a lightly floured surface and knock back the dough and form into an oval. Prove for a further 1 hour.
Preheat the oven.
Place the dough onto an oiled baking tray, slash the top with a sharp knife and sprinkle over the remaining fennel seeds.
Bake for 30 minutes until golden and sounds hollow when tapped.