1.Preheat oven to 220°C. Grease 23cm round sandwich cake pan. Cook bacon in pan, stirring, until crisp; drain, cool.
2.Sift flour into medium bowl, rub in butter. Add bacon, eggs, cheese, chives and mustard, stir in enough milk to mix to a soft, sticky dough.
3.Turn dough onto floured surface, knead until smooth. Press dough out to 2cm thickness, cut into 5cm rounds. Place rounds into prepared pan, brush with a little extra milk, sprinkle with extra cheese.
4.Bake about 15 minutes.