Ingredients for one large challah:
For the egg wash:
Prepare the yeast starter:
In a little bowl stir together the crumbled fresh yeast, a teaspoon of sugar and 50 ml of lukewarm milk (never hot!). Sift some flour on top – less than a tablespoon, cover with a plate and leave in a warm place for about 10 minutes (the yeast mix should increase in volume and show some bubbles by that time).
If you are using dry yeast then omit the above step, just mix the yeast with the flour and the sugar, and follow the recipe as below.
In a mixing bowl of a standing mixer stir the flour with the sugar.
Make a well and pour in the yeast starter and add the lightly beaten egg.
Start working the dough on a lower speed with the dough hook attached. Gradually pour in the water working the dough all the while.
As soon as the water has been absorbed add the salt.
Once all the ingredients all well combined and form a uniform dough, pour in the oil – best if done gradually.
Knead the dough for a further 7 minutes or so. The mixture should turn smooth, shiny and elastic (it can be slightly sticky and a bit dense – the way it should be).
Transfer the dough to a lightly oiled bowl, cover with cling film and leave to rise at room temperature for about two hours or until it doubles in size.
Line a baking tray with a sheet of baking parchment.
Once the dough has risen tip it onto a working space dusted with some flour.
Divide the dough into three of four equal parts.
Take one piece of the dough, flatten it slightly and roll it out into about a 50 cm long strand – if you choose to divide the dough into three parts, or roughly to 40 cm if you choose to braid the bread with four strands. Repeat with the remaining pieces of the dough.
Join the three or four strands together at one end and start to plait them. Keep your plaiting fairly loose in order to give some space for the dough to rise.
Once you reach the ends of the strands, tuck them under (pinch gently if needed) and move your challah to the lined baking tray.
Cover with a tea towel and leave to prove for 30-40 minutes, or until doubled in size.
Preheat the oven to 200 C / 180 C Fan.
Beat the egg yolk with a little bit of milk and lightly brush the challah with the egg wash.
Scatter the sesame seeds on top and bake in the preheated oven for 30-35 minutes until it turns golden dark on top. If the bread top browns too quickly, cover it loosely with a sheet of aluminium foil.
Take the tray out of the oven, transfer the bread on to a wire rack and let it cool down before tearing it apart and enjoying it with lashings of butter.