Into the bowl of your stand-mixer fitted with the hook attachment, sift 660 g of flour; mix in the potato starch, milk powder, salt, sugar, and yeast.

Add the butter and water and knead on low speed until the dough cleans the sides of the bowl. Add more flour as needed.

Knead on low speed for about 6 more minutes, until the dough is soft, smooth, and stretchy (you can you do the windowpane test).

Transfer the dough into a lightly oiled bowl, cover with plastic wrap, and leave in a warm place to proof until doubled in size (about 1–1.5 hours).

Deflate the dough,slightly knead it, and shape it into a loaf.

Place the dough in an oiled 30 x 11 cm loaf pan, cover, and proof for about 1 hour until it rises no more than 5 cm above the pan’s rim.

Meanwhile, preheat the oven to 200 °C (or 180 °C fan).

Brush with water or milk and sprinkle with sesame seeds (this is optional, you can leave it out), and bake on the 2nd lower rack of the oven for 35–40 mins until browned.