Mushroom Sandwiches

The tongue and mushroom mixture can be prepared up to 2 days ahead and stored in an airtight container in the refrigerator. Bring to room temperature for 15 minutes before spreading for easier assembly. The mustard flavor will intensify slightly over time. Do not butter bread or assemble sandwiches until ready to serve.

Store assembled sandwiches wrapped tightly in plastic wrap in the refrigerator for up to 4 hours before serving. For longer storage, keep the filling separate (up to 2 days refrigerated) and assemble fresh sandwiches as needed. The filling can also be frozen for up to 1 month; thaw overnight in the refrigerator before use.