Green Beans with Mustard-Seed Butter

Ingredients

• 4.5 pounds green beans trimmed
• 0.5 cup heavy cream 
• 12 servings salt and pepper freshly ground
• 4 medium shallots thinly sliced
• 0.7 cup sherry vinegar 
• 4 ounces butter unsalted softened
• 0.3 cup water 
• 0.3 cup whole-grain mustard 
• 2 tablespoons mustard seeds yellow

Equipment

• bowl
• frying pan
• pot

Directions

1. In a large skillet, toast the mustard seeds over moderately high heat, shaking the pan frequently, until they pop and start to brown, about 30 seconds.
2. Transfer to a plate and let cool.
3. Add the shallots, sherry vinegar and water to the skillet and simmer over moderately low heat until the liquid is reduced to 1 tablespoon, about 12 minutes.
4. Add the cream and simmer over moderate heat until thickened, about 5 minutes.
5. Transfer to a bowl and let cool to room temperature, then stir in the butter, mustard and toasted mustard seeds. Season with salt and pepper.
6. In a large pot of boiling salted water, cook the green beans until crisp-tender, about 8 minutes.
7. Drain the beans, pat dry and transfer to a large bowl.
8. Add the mustard-seed butter, season with salt and pepper; toss and serve.
9. Make Ahead: The mustard-seed butter can be refrigerated for up to 3 days or frozen for up to 1 month.
10. Let the butter return to room temperature before using. The cooked green beans can be refrigerated overnight; blanch in boiling water or steam until heated through.