The first time I made this, I asked Tim to get me some whole-grain mustard at the store... he was confused, so I clarified by describing the mustard as "the one with all the tiny balls in it." That seemed to work for him.
I've made this chicken recipe a bunch of times and it's really tasty and easy. Made even easier if you use chicken tenders like I did... they don't take very long to cook. I used sage from our rooftop garden. I like the flexibility of this sauce- you can make it as is, or you can splash some cream in. Mmm.