do you proof the yeast or use instant yeast - recipe does not clarify this?

In the very first step, you will mix the dry yeast with the flour, sugar and salt. In the next step, you melt the butter in the milk, which is then added to your flour/yeast dry mixture. It calls for active dry yeast, which is often activated separately in warm water- but if you are careful that you add in the warmed milk at a baby bottle temperature, you can bypass the step. The purpose of rehydrated the active yeast beforehand is to be sure it's alive and kicking. But if you are careful, and are sure the use by date is good, then you should have no problems mixing it in dry as this recipe directs.