Weigh the flour out into a large bowl. Rub in the softened butter using your fingers until the mixture resembles fine crumbs. Add the yeast and sugar to one side of the bowl, and the salt on the other. Using a spatula, mix everything together to combine.
Make a well in the centre and pour in 300ml warm water. Using the spatula, mix until you have a rough dough. Tip the dough out onto the work surface and bring together into a large mound.
Knead the dough by hand for 10-15 mins or in a stand mixer fitted with the dough hook for 6-8 mins on high speed until smooth and elastic. Oil a large bowl and drop in the dough. Cover and leave to prove somewhere warm for 1 hr until doubled in size.
Once the dough has doubled, tip it out onto the work surface and flatten it to remove any air pockets. Sprinkle over the halloumi in an even layer, then the chipotle flakes. Fold the dough over and knead in the cheese and chilli until evenly distributed. Line a large baking tray with baking parchment.
Tuck the edges of the dough into the centre until you have a neat dough ball. Transfer this to the tray, seam-side down, cover with a clean tea towel and leave to prove for another hour until doubled in size again. You will know the dough is ready when you poke it with your finger – if it springs back slowly and a small indent remains, it’s ready.
Heat the oven to 240C/220C fan/gas 7 with a roasting tin on the bottom shelf. Uncover the dough and lightly sieve some flour over it. Cut a cross into the top using the tip of a sharp serrated knife.
Put the loaf on its tray into the roasting tin, then pour some hot water into the tin around the tray to create steam while baking. This will give you a crisp crust. Bake for 20-25 mins until the loaf is golden and sounds hollow when you tap the base.
Remove from the oven and and leave to cool on a wire rack. Cut into slices and enjoy with lashings of butter.
