Combine all rub ingredients together and stir well. Coat tenderloins thoroughly with rub mixture. Refrigerate for up to 12 hours. You’ll achieve the best flavour by allowing the rub to infuse for several hours, but even if you only have a short time, the flavour shines through.
Preheat oven to 350 F (175 C). Brush baking pan with 1 Tbsp olive oil. Allow tenderloins to stand at room temperature for 30 minutes before cooking. Roast for 15 to 20 minutes, or until pork achieves an internal temperature of 145 F (63 C). Remove from oven, cover pork, and let it rest for 15 minutes while you prepare salad.
In large bowl, mix olive oil, vinegar, shallot, mustard, salt, and pepper together, and gently toss with arugula. Arrange leaves on large platter. Slice pork and arrange over salad. Garnish with pomegranate seeds.