Rogale (Polish brioche crescents) (Grace Mazur)

Dough

• 210 g full cream milk
• 20 g fresh yeast (see Tips)
• 2 tbsp raw sugar
• 60 g unsalted butter, melted
• 2 tbsp grapeseed oil (see Tips)
• 1 pinch salt
• 3 egg yolks
• 500 g plain flour, plus extra to dust

Filling

• 150 g prosciutto, cut into thin slices
• 200 g Swiss cheese, cut into thin slices
• 1 egg yolk, lightly beaten, to glaze
• 2 tbsp sesame seeds (optional)