Roux

1. Combine the water and flour in a small saucepan and whisk on medium heat until thickened into a paste
2. Remove from the heat, cover, and cool until room temperature

Dough

1. Combine bread flour, all-purpose flour, milk powder, sugar, salt, and yeast in the bowl of a stand mixer fitted with a dough hook attachment
2. Add the egg, water, and cooled roux and knead on medium for 3 minutes or until a rough dough forms
3. Add the butter and continue to knead for 15-20 minutes until the dough is smooth and elastic (if kneading by hand this process will take from 20-30 minutes)
4. Roll the dough into a ball and place it in an oiled large bowl
5. Cover loosely with plastic wrap and place in a warm place for 1-2 hours or until doubled in size
6. Transfer the proofed dough to a lightly floured surface and press out the excess air
7. Divide the dough into 8 equal portions and roll them into balls
8. Prepare a 9-inch round cake tin or any baking dish of your choice, and line the bottom with parchment paper
9. Arrange the 8 balls of dough in the dish
10. Cover with plastic wrap and place in a warm place to proof for 30 minutes, or until almost doubled in size
11. Meanwhile, preheat the oven to 180C/355F
12. Bake for 25 minutes or until the buns are golden brown and spring back when touched (the internal temperature should be 190F/88C on an instant-read thermometer)
13. Meanwhile, prepare the garlic butter

Garlic Butter

1. Melt the butter in a small saucepan or in the microwave
2. Add the salt, garlic and spring onion, and stir to combine
3. Once the rolls come out of the oven pour over garlic butter and allow it to soak into the bread
4. Cool for 10 minutes and sprinkle with flaky salt to serve