Roast Prime Rib with Horseradish Sauce

Ingredients

Prime Rib

• 1 (8 pound) prime rib roast
• 1 tablespoon dry mustard
• 1 tablespoon ground black pepper
• 1 tablespoon soy sauce
• 1 medium onion, sliced

Horseradish Sauce

• 1/4 cup prepared horseradish
• 1/2 cup mayonnaise
• 1/4 cup sour cream

Instructions

1. Heat oven to 450 degrees F.

Prime Rib

1. Rub the seasonings on the roast and place on a rack in roasting pan. Place the onions on top of the roast. Place in oven for 25 minutes.
2. Reduce heat to 325 degrees F, and roast for one hour longer or until internal meat temperature reaches 115 degrees for rare. Cook for an additional 20 minutes for medium.
3. Let stand for 15 minutes before carving.

Horseradish Sauce

1. Combine all ingredients and chill.
2. Serve with prime rib.