Prepare the Dough: In a large bowl, combine the bread flour, sugar, yeast, and salt. Mix well.

In a separate bowl, whisk together the egg and milk. Gradually add this mixture to the dry ingredients, mixing until a dough forms.

Add the 30g of unsalted butter to the dough and knead until smooth and elastic, about 10 minutes.

Cover the dough with a damp cloth and let it rise in a warm place for about 1 hour, or until doubled in size.

Preheat the Oven: Preheat your oven to 175°C (350°F).

Shape the Dough: Punch down the dough and roll it out into a rectangle.

Spread the 80g of softened butter evenly over the dough.

Sprinkle with chopped scallion, black pepper, and additional salt to taste.

Roll the dough into a log and cut into equal pieces.

Prepare for Baking: Place the pieces in a greased baking dish.

Brush with egg wash and sprinkle with sesame seeds.

Bake the Bread: Bake in the preheated oven for 25 minutes, or until golden brown.

Let the bread cool slightly before serving.