Soy Mustard Pork Tenderloin

Preparation

1. Step 1

   Combine 3 tablespoons of the soy sauce and the mustard in a small bowl. Place the pork tenderloins in a shallow dish and rub all over with the marinade. Let stand for 1 hour.

2. Step 2

   Preheat oven to 375 degrees. Heat the olive oil in an overproof, flameproof roasting pan over medium-high heat. Wipe the marinade off of the pork, place in the pan and sear until browned, about 1 minute per side.

3. Step 3

   Roast the tenderloins until they are only slightly pink in the center, about 15 minutes, turning them once. Remove the pork from the pan and tent with foil to keep warm. Add the remaining 1 teaspoon soy sauce and the sake or mirin to the pan and cook over medium-high heat, stirring constantly and scraping up any browned bits stuck to the bottom, about 2 minutes.

4. Step 4

   Add the mushrooms and the scallions and cook until soft, about 5 minutes. Season with pepper. Slice the tenderloins into ¼-inch thick slices and divide among 4 plates. Spoon the mushroom sauce over the pork and serve immediately.