Beef Tenderloin with Shallot Sauce

My in-laws made this wonderful Southern Living dish for Christmas dinner.  It was a big hit with the whole family!  This would make a great meal anytime you're entertaining for a large crowd - it serves 16!

Beef Tenderloin with Shallot Sauce
Ingredients:
1 pound shallots, peeled and halved lengthwise
2 tablespoons olive oil
3/4 teaspoon salt
1/2 teaspoon pepper
1 tablespoon salt
1 1/2 teaspoons onion powder
1 1/2 teaspoons garlic powder
1 1/2 teaspoons pepper
1 1/2 teaspoons chopped fresh thyme
1 (8-pound) beef tenderloin, trimmed (see note)
1/4 cup olive oil
3 cups beef broth
1 cup dry Marsala wine
2 tablespoons all-purpose flour
3 tablespoons water
3 tablespoons butter
1/4 teaspoon pepper
Garnish: fresh thyme

Directions:
Toss shallots and 2 tablespoons oil in a bowl; stir in 3/4 teaspoon salt and 1/2 teaspoon pepper.  Set aside. 

Stir together 1 tablespoon salt and next 4 ingredients.  Rub tenderloin with 1/4 cup olive oil; sprinkle seasonings over top and sides of tenderloin, pressing gently with fingers.  Place tenderloin in a large lightly greased roasting pan; arrange shallots around tenderloin. 

Bake, uncovered, at 500 degrees for 25 minutes.  Reduce oven temperature to 375 degrees and bake 15 to 20 minutes or until a meat thermometer inserted into thickest part of tenderloin registers 145 degrees (medium-rare) or 160 degrees (medium). 

Meanwhile, stir together beef broth and Marsala in a large skillet.  Bring to a boil; boil 8 minutes or until liquid is reduced to 2 cups. 

Remove tenderloin to a serving platter, and cover with aluminum foil; reserve shallots and drippings in pan.  Add broth reduction to pan, and place over medium heat on cook top, stirring to loosen particle from bottom of pan. 

Whisk together flour and water until smooth; stir into sauce in roasting pan.  Cook over medium heat 3 minutes, or until sauce is slightly thickened, stirring constantly.  Add butter, stirring just until melted.  Stir in 1/4 teaspoon pepper.  Thinly slice tenderloin and serve with sauce.  Garnish if desired.

Note:  Find beef tenderloin sealed in plastic in the meat section of your super market.  Once you trim the tenderloin, you should yield about 6 pounds of meat.  To save time, ask your butcher to trim it for you.