Potato Buns

Potato buns

• 200 g Russet potatoes cut in cubes (1 cm)
• 70 g water
• 120 g fresh milk room temperature
• 1 tsp dried yeast
• 70 g sugar
• 1 egg
• 450 g high protein flour
• 40 g butter softened, plus extra for greasing
  或 40 g olive oil plus extra for greasing
• ¼ tsp salt

Custard cream

• 300 g fresh milk
• 10 g butter
• ½ tsp vanilla extract
• 10 g plain flour
• 15 g cornflour (starch)
• 75 g sugar
• 3 egg yolks
• 2 tsp custard powder instant
• 1 egg lightly beaten