Mustard-Seed-Crusted Prime Rib Roast with Roasted Balsamic Onions

Ingredients

• 1 ½ teaspoons coarse kosher salt plus additional (for sprinkling)
• ¼ cup brandy
• ½ cup heavy whipping cream
• ½ cup crème frache
• ¼ cup prepared white horseradish
• 51 teaspoons dijon mustard
• 4 medium onions
• + 8 more ingredients
• • 4 garlic cloves, minced
  • 1 9 1/2-pound bone-in standing prime rib roast, trimmed
  • 2 tablespoons yellow mustard seeds
  • 2 cups low-salt beef broth
  • Chopped fresh italian parsley
  • 5 very large shallots
  • 3 tablespoons balsamic vinegar
  • 2 tablespoons olive oil

Using electric mixer, beat crème fraîche and cream in medium bowl to firm peaks. Fold in horseradish and 1/3 cup mustard. Season to taste with salt and pepper. Cover and chill. DO AHEAD: Can be made 8 hours ahead. Keep chilled. Rewhisk before serving. Preheat oven to 450°f. Toss onions, shallot...

View full recipe at Epicurious