Warm the buttermilk (or milk and yoghurt mixture) for 1 minute in a microwave on full power. The liquid temperature should be tepid to warm - enough to encourage the yeast to start working but not hot enough to kill it. If you don’t have a microwave, gently warm the liquid in a saucepan.
Add all your ingredients to the mixer bowl of a free standing mixer fitted with dough hook.
Mix on slow speed number 1 for approximately 1 to 2 minutes then on speed number 2 for 8 to 10 minutes. Your dough should be lovely and smooth and elastic.
Place your dough in a large greased mixing bowl and cover.
Leave to rest in a warm place for at least one and a half hours or until doubled in size.
Transfer the dough to a lightly floured work surface and divide into 3 portions. Roll each portion with your hands into a 35 cm long sausage shape.
Lay the 3 dough sausages in front of you and begin plaiting from the centre, left over right, right over left etc.
When you reach the end, turn your plait and repeat, plaiting in reverse order.
Press the ends together and tuck them in to neaten before placing in your loaf tin.
Cover and leave to rise for about 45 minutes or until doubled in size.
Brush your loaf with egg wash.
Bake in the oven the 35 to 40 minutes until golden brown.