Delicious sauce - love the rich tangy taste of the mustard and vinegar! We are grilling a nice flat-iron steak tonight and this sauce will go great with it! I did not have any shallots, so I used a red onion and it turned out great. We are big fans of whole grain mustard so I plan to make it again for grilled veggies and grilled meats. Made for Everyday is a Holiday, May 2012.