This is an older recipe from 2016 that I updated in 2020. If you made it before the update, you may have noticed that the instructions have changed a bit. In the original version I had you adding the wine and letting it reduce before adding the flour. I discovered recently that potatoes cook up softer and faster in the absence of wine, which is why it goes in later now. Feel free to stick with the original process if you prefer - just add the wine between steps 3 and 4, and let it simmer for 4 or 5 minutes to reduce.