courtesy of Williams Sonoma

The flavors of the Italian pork dish known as porchetta inspired the marinade for these quick-cooking tenderloins, which are seasoned with fresh rosemary, fennel seeds, red pepper flakes, garlic and citrus. This marinade is also delicious with shrimp and chicken.

Ingredients
Zest of 1 orange
1/2 cup (4 fl. oz./125 ml) fresh orange juice
2 Tbs. fresh lemon juice
1/4 cup (2 fl. oz./60 ml) olive oil
1 Tbs. fennel seeds
1 Tbs. minced garlic
1 1/2 tsp. chopped fresh rosemary, plus sprigs for garnish
1/4 tsp. red pepper flakes
1 Tbs. Dijon mustard
1 Tbs. kosher salt
1/4 tsp. freshly ground black pepper
2 pork tenderloins, each 1 to 1 1/4 lb. (500 to 625 g)
1 orange, sliced


Method

1. In a bowl, whisk together the orange zest, orange juice, lemon juice, olive oil, fennel seeds, garlic, chopped rosemary, red pepper flakes, mustard, salt and black pepper. Pour the marinade into a large resealable plastic bag. Add the pork tenderloins, seal the bag and refrigerate for 2 hours.
2. Remove the pork from the marinade; discard the marinade. Preheat a cast-iron grill pan over medium-high heat until hot, about 5 minutes. Place the pork on the grill pan and cook, turning occasionally, until nicely grill-marked and an instant-read thermometer inserted into the center of the meat registers 140°F (60°C), 25 to 30 minutes. Transfer the pork to a cutting board, cover loosely with aluminum foil and let rest for 10 minutes.
3. Meanwhile, place the orange slices on the grill pan and cook, turning once, until nicely grill-marked, 1 to 2 minutes per side. Cut the pork into slices and arrange on a warmed platter. Garnish with the orange slices and rosemary sprigs and serve immediately.