Mix 500g flour, 7g yeast, 50g sugar, and 1 tsp salt.
Add 2 eggs and 225ml buttermilk (or milk ,buttermilk can be made with just one ingredient - see butter recipe). Mix into a dough.
Knead for 8–10 minutes until smooth.
Gradually knead in 100g softened butter until fully incorporated.
Let rise until doubled (about 1–2 hours).
Divide into 8-12 equal pieces and shape into balls.
Place on a baking tray and let rise again until puffy (45–90 minutes).
Brush with beaten egg.
Bake at 190°C (170°C fan) for 15–18 minutes until golden brown.