Step 1

In a large bowl, whisk together the vinegar, brown sugar, mustard, garlic, seasonings, and 2 tablespoons of the olive oil until evenly combined. Place the turkey in the bowl with the marinade and toss to coat. Cover and refrigerate for at least 30 minutes, up to overnight, to let the flavors infuse.

Step 2

Preheat the oven to 400 F.

Step 3

Heat the remaining tablespoon of oil in a cast iron or other oven-safe skillet over medium-high heat.

Step 4

Once hot, place the tenderloins in the pan, working in two batches if needed to prevent over-crowding. Sear for 3-4 minutes per side, until browned.

Step 5

Transfer the pan to the oven and cook for 30-40 minutes, or until a thermometer inserted into the thickest part of the tenderloin registers 165 F.

Step 6

Remove the turkey from the oven and let rest for 10 minutes, then slice and serve.