1. Place water in a bowl and dissolve the yeast. Add the milk and beaten egg.
2. Place the flour, salt, sugar and butter in the bowl fitted with the kneading/ crushing blade. Launch the P1 pastry program. After 30 seconds, add the liquid with the yeast. After 2 minutes 30 seconds of mixing your dough should be shaped like a ball. Be careful to leave it in the Prep&Cook to rise for the next 40 minutes of the program.
3. Using a spatula, remove the dough from the bowl and separate into 4 to 6 equal pieces. Form into balls and place on a tray lined with baking paper and flatten with the palm of your hand. Leave to proof for 1 hour 30 seconds.
4. Preheat the oven to 350°F. Brush the buns with egg yolk and sprinkle with sesame seeds. Bake for 15 to 20 minutes. Leave to cool on a rack