Add the egg to a stand mixer bowl and give it a quick mix.
Add the butter and milk and give it another quick mix (the butter will not dissolve or mix very well, but that's okay).
Add 250g (2 cups) of flour along with the yeast, salt and sugar. Mix until everything is well combined.
Gradually add as much flour as needed. I add one tablespoon at a time. Too much flour will result in dry bread, so it is much better to have less flour than too much. Your dough should be sticky. A good rule of thumb for me is that when the dough starts to pull away from the bowl, and the stand mixer starts to bang a little more, the dough is ready.
Change to a kneading attachment tool (if you have one) and knead for five minutes. The dough will still be sticky, but will easily come away from the attachment when pulled gently.
Cover and leave until doubled in size. This is usually around 60 minutes, but the time will vary (if you've used cold butter, eggs and milk, then the proofing will take longer).
Pour out the dough on to a very well-floured surface (the dough is still very sticky). Quickly knead and incorporate the flour until your dough is smooth and manageable. Cover and leave for another 20 minutes.
Pre-heat the oven to 180℃ (356℉) and line a large baking tray with baking paper.
Cut dough into 4 equal pieces (I weighed mine). Roll each one out into a length of around 5cm x 20cm (2" x 7¾"). Tuck the bottoms under and pinch the seam.
Place seam side down on the baking tray with a small gap of around 2cm (¾") between them.
Cover and allow the dough to rest for a further 20 minutes.
Give the four buns a liberal brush of egg and diagonally slash each one three times.
Bake for around 12 minutes (keep a very close eye and start checking at 10 minutes). The buns will be golden on top but still soft. Tap the bottoms, and if they sound hollow, they are ready.
Allow the bread to cool completely before using. As it is fresh bread, it doesn't take long for them to harden up a little, so pop any not eaten straight away in the freezer. Enjoy!