Beef And Horseradish Sauce Sandwich - cooking recipe

Ingredients

BEEF
2 -3 lbs filet of beef, trimmed and tied
1 tablespoon unsalted butter, room at temperature
1 teaspoon Dijon mustard
2 teaspoons kosher salt
2 teaspoons fresh coarse ground black pepper
SAUCE
3/4 cup good mayonnaise (Hellmans)
1 1/2 tablespoons Dijon mustard
1 tablespoon whole grain mustard
1/2 teaspoon white prepared horseradish
2 tablespoons sour cream
kosher salt
FOR THE SANDWICH
1 loaf unsliced health bread or 1 loaf unsliced multi-grain bread
arugula
kosher salt
fresh ground black pepper
unsalted butter, at room temperature

Preparation

TO COOK THE BEEF:
Preheat oven to 500\u00b0F.
Place the beef on baking sheet and pat the outside dry with a paper towel.
Mix the unsalted butter and mustards together in a small bowl and spread the mixture over the beef with your hands.
Sprinkle evenly with the salt and pepper.
Roast in the oven for exactly 22 minutes for rare and 25 minutes for medium-rare.
Remove the beef from oven, cover lightly with aluminum foil, and allow it to rest at room tempearture for 20 minutes. Remove the strings and slice fillet thickly(personal preference, I like mine thin).
SAUCE:
Whisk together all ingredients in a small bowl. Serve at room temperature.
TO MAKE THE SANDWICH:
Cut the bread into 1/4\" thick slices.
Spread 4 of the slices thickly with the Mustard Horseradish Sauce.
Top with slices of beef and arugula and sprinkle with salt and pepper.
Spread 4 more slices of bread very lightly with butter and place butter side down, on top of the beef.
Enjoy, they are divine!