Peel and finely chop the shallots

Remove leaves from parsley stems and finely chop the leaves. Place shallots in a medium saucepan with wine

Bring to a boil and cook until most liquid evaporates, about 4 minutes

Add the whipping cream and bring to a simmer

Cook until sauce is reduced slightly, about 2 minutes

Whisk in the mustard and simmer for 2 minutes longer to blend flavors

Season to taste with salt and pepper and stir in parsley.