Haricots Verts with Warm Mustard Vinaigrette

If you don't have stone-ground mustard already in your fridge, Dijon would work equally well in this bright and tangy veggie side dish. You can also opt to use microwave-in-bag green beans instead of the slightly more delicate haricot verts--just increase your cook time in the pan by 1 to 2 minutes, or until beans are crisp-tender.