Chop the scallions and sliced cheese into small pieces.
On a dry pan, lightly saut the chopped scallions on low heat, until it turns light brown. Transfer them to a plate and let it cool completely.
In a large bowl, sift flour, baking powder, salt, and sugar.
Dice the butter into small pieces. Make sure the butter is cold and firm, straight from the fridge.
In the bowl with the flour mixture, add the diced butter and, with your fingers, gently rub the butter with the flour mixture. They should not melt, but should be crumbled into a size of a grain and fully covered with flour.
Beat the egg and add half of the mixture into the bowl. Add scallions, milk, and cheese and mix it slightly but thoroughly with a fork. Once the dough starts to stick together, clump it into one large lump.
Cover the bowl with a plastic wrap and leave it in the fridge for at least an hour.
Cut the dough into 4 even pieces, and brush the top with the leftover beaten egg. Bake in the oven for about 20-25 minutes at 180 degrees celsius, until golden brown. Serve warm.
