Step 1: Preheat the Oven

1. Preheat Oven: Preheat your oven to 400°F (200°C).

Step 2: Prepare the Pork Tenderloin

1. Trim and Season: Trim any excess fat from the pork tenderloins. Pat them dry with paper towels. Season generously with salt and pepper.
2. Add Flavor: In a small bowl, mix the chopped rosemary and minced garlic with olive oil. Rub this mixture all over the pork tenderloins.

Step 3: Sear the Pork

1. Sear: In an oven-safe skillet over medium-high heat, add a bit of olive oil. Sear the pork tenderloins for about 2-3 minutes on each side until browned.

Step 4: Make the Orange Glaze

1. Combine Ingredients: In a small saucepan, combine the orange juice, orange zest, honey, Dijon mustard, soy sauce, chopped rosemary, and red pepper flakes (if using). Bring to a simmer over medium heat.
2. Thicken Glaze: Let the glaze simmer for about 5-7 minutes until it thickens slightly.

Step 5: Roast the Pork

1. Glaze the Pork: Brush some of the orange glaze over the seared pork tenderloins.
2. Roast: Place the skillet in the preheated oven and roast for 15-20 minutes, or until the internal temperature reaches 145°F (63°C). Brush with additional glaze halfway through cooking.

Step 6: Rest and Serve

1. Rest: Once cooked, remove the pork from the oven and let it rest for 5-10 minutes before slicing. This helps the juices redistribute.
2. Serve: Slice the pork tenderloin and drizzle with the remaining orange glaze. Garnish with additional fresh rosemary if desired.