Mustard seed encrusted prime rib

Preheat the oven to 450 degrees. Season the roast with salt and pepper. Mix the garlic with the mustard and spread on the roast. Sprinkle and press in the mustard seed. Roast in the oven for 20 minutes. Reduce heat to 350 degrees. Mix the onions, shallots, vinegar and olive oil. Arrange around the roast and continue to cook for about 2 hours. Remove and allow to rest on a cutting board covered with aluminum foil.

Remove the onions and shallots from the roasting pan and discard. Add the brandy to the pan and deglaze over a medium flame until the liquid is reduced by half. Add the broth and simmer for 10 minutes, stirring occasionally. Serve with the sliced prime rib and horseradish sauce.