What is Diane sauce?

There is no sauce called "Diane sauce." It's possible you may have misheard or misspelled the name of a sauce. Here are some possibilities:

* Sauce Diane: This is a classic French sauce made with butter, white wine, lemon juice, and herbs. It's often served with chicken or fish.

* Sauce Béarnaise: This rich, emulsified sauce is made with egg yolks, butter, vinegar, tarragon, and other herbs. It's traditionally served with steak.

* Sauce Mornay: This creamy sauce is made with béchamel sauce, Gruyère cheese, and often nutmeg. It's typically used in gratins and other baked dishes.

If you can provide more context about where you heard the term "Diane sauce," it may be possible to figure out the correct name of the sauce you're thinking of.