Set the prover to 25℃ (77℉)
Add the bread flour into the mixing bowl followed by sugar, salt and yeast in separate corners of the bowl so they are not touching.
Set on the mixer with a dough hook attachment and start mixing on a low-medium speed. Slowly pour the water into the mixer until a rough dough has formed. Scrape down the bowl and mix for 2 minutes on a medium speed. (We just want to activate the gluten before adding in fats).Add the butter in a tablespoon at a time, allowing it to incorporate before adding more. Once it is all combined, turn the mixer up to high and mix for 5-7 minutes. You are looking for a smooth, elastic dough (window pane). Lightly flour your work surface and turn the dough out. Pinch a corner of the dough, stretch outwards and fold over onto itself to the centre of the dough. Continue to do this working your way around the dough to form a rough ball. With your dough scraper scoop up the dough and turn over. Use the dough scraper to roll and tuck the dough to form a smooth and tight ball. Place into a lightly greased bowl and cover with cling film (or shower cap) then into the prover for 50 minutes - 1 hour or doubled in size. Lightly grease the loaf tin.Turn the dough out onto a light floured work surface so the top of the dough is at the bottom (refrain from punching the air out). Gently stretch the dough into a vertical rectangle 30cm x 40cm (11in x 15in). From the top-down, roll the dough tucking it in on itself with your thumbs. Pinch the ends and side where the dough meets to seal and place into the loaf tin seam side down, cover with cling film and back into the prover for 30 minutes. (The dough should rise to about 80% of the tin height) In the meantime preheat the oven to 200℃ (390℉). When the dough is ready, milk wash the top and into the oven for 30-35 minutes. If you tap the bread it should sound hollow.
Cool in the tin for 20-30 minutes then turn out onto a wire rack to cool down for another hour or 2.
