Can you make duck saille ahead of time for beef wellington?

Elizabeth, I think you too have been affected by autocorrect! (Bane of my existence!). Yes, you can make the duxelles ahead, and even freeze them. Leftovers can make a great omelet filling or the basis of a tasty soup!

I believe you're referring to duxelles, the mushroom pate that covers the beef before wrapping in puff pastry. And yes you can..