You can serve these quick and easy green beans any time of year, not just during the holidays. Add the sour cream at the last minute.
Combine first 4 ingredients; set aside.
Steam green beans, covered, 5 minutes or until tender. Keep warm. Melt butter in a Dutch oven over medium heat. Add shallots; sauté 3 minutes. Stir in mustard mixture and green beans; toss well. Cook for 2 minutes or until thoroughly heated. Stir in sour cream, and remove from heat. Serve immediately.
This is a good recipe, but not holiday-worthy. I made it for Thanksgiving this year. Everyone agreed that it was fine for an everyday dish, but nothing special.