MUSTARD-CRUSTED BEEF TENDERLOIN WITH ARUGULA, RED ONION, AND WAX BEAN SALAD

Mustard-Crusted Beef Tenderloin with Arugula, Red Onion, and Wax Bean Salad image

Yield Makes 2 servings

Number Of Ingredients 17

For beef
1/4 cup coarse-grain mustard
3/4 teaspoon dry mustard
2 1/4 teaspoons packed dark brown sugar
3/4 teaspoon coarsely ground black pepper
1/2 teaspoon finely grated fresh lemon zest
1 (1-lb) trimmed beef tenderloin roast, tied
1 tablespoon vegetable oil
For salad
1 small red onion (1/4 lb), thinly sliced
1/2 lb wax or green beans, cut diagonally into 2-inch pieces
4 oz baby arugula (4 cups)
For dressing
1 1/2 tablespoons balsamic vinegar
1 tablespoon fresh lemon juice
1/4 teaspoon Dijon mustard
1/4 cup olive oil

Steps:

Prepare beef:
Preheat oven to 425°F.
Stir together mustards, brown sugar, pepper, and lemon zest.
Pat beef dry and season generously with salt. Heat oil in a heavy skillet over moderately high heat until just beginning to smoke, then brown beef on all sides, about 2 minutes total.
Transfer to an oiled shallow baking pan and coat with mustard mixture.
Roast beef in middle of oven until a thermometer inserted 2 inches into thickest part of meat registers 125°F for medium-rare, 15 to 20 minutes. Transfer to a cutting board and let stand until cool, at least 45 minutes.
Prepare salad while beef is roasting:
Chill onion slices in water to cover 30 minutes. Cook beans in boiling salted water until crisp-tender, about 5 minutes. Drain beans in a colander and rinse under cold water to stop cooking, then transfer to a large bowl. Add arugula to beans. Drain onion slices and pat dry.
Make dressing and toss salad:
Whisk together vinegar, lemon juice, mustard, and salt and pepper to taste. Add oil in a slow stream, whisking until emulsified.
Cut beef into thin slices.
Add onion slices, beef, and enough dressing to arugula and beans to just coat and toss to combine well.