Boy are you in luck!
I cook a ****ake sauce for beef tenderloin that's the bomb.
Saute shrooms in butter to soften (3-5 minutes) medium heat, add 1 tablesppon of madira wine (ish), let evaporate, then add 3/4 cup of beef stock and 1/4 cup whipping cream. Bring to boil for 1 minute, then simmer; add 2 tablespoons of full grain dijon and some fresh parsley. Simmer 5 minutes, serve
Spread over tenderloan when it's cooked.
You can also add a little truffle oil if it's for the right lady
Let me know how it turns out
Bob