In a dish, add yeast to lukewarm WATER & allow to sit for 5 minutes so yeast can activate. In a large bowl, whisk together lukewarm MILK, sugar, butter, salt & egg. Add yeast mixture & stir to combine. Add flour, about a 1/3 at a time, combining after each addition. Once all the flour has been added, knead on a lightly floured surface for about 2 minutes. The dough should be elastic & slightly sticky but easy to handle.