Roast Beef With Horseradish Sauce

Saw this in the March, 2010 issue of Good Housekeeping. Thought some adventurous chefs might like to try this. I MIGHT try it someday...before I get REALLY old can't comprehend written directions any more!

• Ready In: 45 mins
• Serves: 6

Ingredients

• 4  garlic cloves
• 2  sprigs fresh rosemary
• 1  tablespoon olive oil
• 1  teaspoon olive oil
•  salt and pepper
• 2 1⁄2 lbs yukon gold potatoes, cut in half, cut in quarters if large
• 1  whole tri-tip steak, roast (sirloin tip, 2 to 2 1/2 lbs.)
• 1⁄4 cup  whipping cream
• 2  tablespoons  prepared horseradish
• 1⁄2 teaspoon Dijon mustard
• 1⁄2 teaspoon white wine vinegar

Directions

1. Preheat oven to 475 degrees. With side of knife, gently smash 3 cloves garlic; discard peel. Into small bowl, crush remaining clove garlic with press. Cut 1 rosemary sprig into 1-in. pieces; set aside. Remove leaves from other sprig; discard stem. Finely chop leaves and add to bowl with crushed garlic along with 1 teaspoons oil, 1/4 teaspoon salt, and 1/4 teaspoon freshly ground black pepper; set aside.
2. In 18" X 12" jelly-roll pan, combine potatoes, remaining 1 tablespoon oil, smashed garlic, snipped rosemary, 1/4 teaspoons salt, and 1/4 teaspoons freshly ground black pepper until well mixed. Spread in even layer, making space in center of pan for beef. Place beef in center of pan, fat side down; rub with reserved garlic-rosemary mixture.
3. Roast 20 minutes or until beef browns. Reset oven control to 350 degrees. Roast 8 to 10 minutes or until temperature on meat thermometer, inserted into thickest part of beef, reaches 130 degrees F. Transfer to cutting board. Cover loosely; Let stand 10 minutes. Transfer potatoes to platter.
4. Meanwhile, whisk cream, horseradish, mustard, vinegar, 1/8 teaspoons salt and 1/8 teaspoons freshly ground black pepper until well blended. Slice meat thinly. Serve with potatoes and horseradish cream.