For the sauce, melt the butter in a small saucepan. Add the flour and whisk for a good minute, until well combined and that flour taste is gone. Slowly add in the cream and wine; whisk until combined. Simmer and reduce the sauce for about 5 minutes. Add in the parmesan cheese and a good pinch of salt and pepper. Continue to simmer another 5 minutes. Taste. Add a little more salt if needed.