Beef Tenderloin Sandwiches with Spicy Mustard

1 . Stage

Coat steaks all over with peppercorns. Cover and refrigerate for 30 minutes, or up to 24 hours.

2 . Stage

Mix mayonnaise, mustard, and horseradish together in a small bowl. Cover and refrigerate with steaks.

3 . Stage

When ready to cook, toss mushrooms and lemon juice together in a medium bowl until mushrooms are evenly coated. Sprinkle lightly with salt.

4 . Stage

Generously brush a large, heavy skillet with oil and heat over medium-high heat. Add steaks and cook to desired doneness, about 5 minutes per side for medium-rare. An instant-read thermometer inserted into the center should read 130 degrees F (54 degrees C). Transfer steaks to a plate and let stand for 15 minutes before slicing thinly.

5 . Stage

After the steaks have sat for about 5 minutes, place bacon in the same skillet and cook over medium-high heat, turning occasionally, until brown and crisp, about 10 minutes. Use tongs to transfer bacon to paper towels to drain.

6 . Stage

Place roll bottoms on plates. Spread with mustard dressing. Divide sliced steak among rolls. Top with bacon, mushrooms, and arugula, then cover sandwiches with roll tops.