Dissolve the fresh yeast in the lukewarm milk with the sugar, then pour the mixture into the bowl of a stand mixer.
Add the rest of the ingredients and knead with the dough hook for 8 to 10 minutes until the dough is soft and elastic.
Place the dough in a greased bowl and cover with plastic wrap.
Let it rise for about 2 hours until it has doubled in size.

On a lightly floured surface, divide the dough into 8 pieces.
Shape into small balls and place them, spacing them well, on two baking sheets lined with parchment paper.
Let them rise until the dough has doubled in size, about 1 hour.

Preheat the oven to 400°F (200°C).
Beat the egg with cold water and brush the buns with it.
Sprinkle with sesame seeds to taste.

Bake for 25 minutes or until the buns are golden brown.