How to Make It
Step
In a large bowl, combine the sherry vinegar, salt and pepper and whisk until the salt dissolves; stir in the mustard, Gradually whisk in the olive oil in a thin steady stream until the mixture emulsifies. Add the parsley, endive and prosciutto and toss the coat with the dressing.
Make Ahead
The dressing can be refrigerated for up to 2 days.
