Step 1

Mix the flours, yeast and salt in a very large bowl. Measure 350ml/12fl oz lukewarm water in a jug, then stir in the treacle and oil until the treacle has completely dissolved. Make a dip in the middle of the flour mixture and pour in the water mixture. Mix in the water with a cutlery knife.

Step 2

Tip the dough onto a very lightly floured surface and knead by hand for 10 minutes until it feels smooth and elastic (or you can mix and knead the ingredients in a freestanding mixer fitted with a dough hook attachment). Wipe out the bowl so it is free of flour, lightly oil and then place the dough back in. Cover with an oiled plate or sheet of oiled cling film and leave for 45 minutes–1 hour until the dough has doubled in size and feels light and springy. The temperature of the room will affect how quickly it rises.

Step 3

Knock back the dough lightly to remove any large air bubbles, kneading just 4–5 times. Lightly oil a 900g/2lb loaf tin and line the base and ends with a long strip of baking paper. Shape the dough into a smooth oval and place in the loaf tin. Cover with a clean tea towel and leave to prove until the dough has risen to almost fill the tin – usually about 35–50 minutes. It should no longer spring back when pressed with a finger.

Step 4

Preheat the oven to 220C/200C Fan/Gas 7 with a roasting tin in the bottom. Put the loaf tin in the oven and pour about 250ml/9fl oz water into the preheated roasting tin. The water will give a burst of steam to create a crisp crust. Shut the door quickly, lower the heat to 200C/180C Fan/Gas 6 and bake the loaf for 30–35 minutes until the loaf is risen and golden. Carefully lift the bread from the tin and tap the base to check it sounds hollow. Leave to cool on a wire rack.