1 - step 1
Combine the yeast, a pinch of the sugar and a couple tablespoons of lukewarm water in a small bowl.
2 - Stir to dissolve the yeast, then leave for 10 mins until foamy.
3 - step 2
Meanwhile, combine the flour, the remaining sugar and 2 tsp fine salt in a large bowl.
4 - Make a well in the centre, then add half the beaten egg, the yeast mixture and the oil.
5 - Pour in 200ml lukewarm water (it should feel slightly warm to the touch) and stir with a spoon, then mix using one hand, keeping the other clean while you bring the dough together.
6 - If there are a lot of very dry bits, gradually add a little water to just bring it together – you don't want it to get too wet and sticky.
7 - The dough should be moist, but not soggy.
8 - step 3
Once the dough has come together, turn it out onto a lightly floured surface.
9 - Knead using both hands for 10 mins until smooth and a bit springy.
10 - If it gets very sticky, add a very small amount of flour – as little as possible.
11 - A dough scraper is useful if the dough is sticking to the work surface.
12 - Stretch the sides of the dough down and pull together to form a ball.
13 - Lightly oil a bowl, then lightly roll the dough ball around the bowl so it's coated in the oil.
14 - Cover with a clean tea towel and leave in a warm place for 1 hr, or until dough has doubled in size.
15 - step 4
Line a baking sheet with baking parchment.
16 - Turn the dough out onto a clean work surface and divide into three equal pieces, weighing for accuracy, if you like.
17 - Roll each piece into a long sausage shape about 25cm long, tapering them slightly at both ends.
18 - Lay the pieces out in front of you, parallel to one another with a couple centimetres between each.
19 - Bring the sausages together at the top end, then plait them down the length, tucking in the ends when you reach the bottom.
20 - Carefully transfer the loaf to the prepared baking sheet and loosely cover with a clean tea towel.
21 - Leave to rise until puffy and billowy, about 40 mins.
22 - step 5
Meanwhile, heat the oven to 200C/180C fan/gas 6.
23 - Gently brush the rest of the beaten egg all over the challah, getting it into all the crevices, and sprinkle with the poppy or sesame seeds, if using.
24 - Bake on a middle shelf of the oven for 25-30 mins, until the loaf is golden brown underneath and sounds hollow when tapped.
25 - Check after about 15 mins – if the top of the loaf has started to get too dark, cover it with foil.
