Step 1

Trim any silverskin off the tenderloins and transfer to a sturdy resealable plastic bag.

Step 2

Make the marinade: Combine the red wine, garlic, soy sauce, and red wine vinegar in a small mixing bowl and whisk to combine. Stir in the chopped rosemary and the pepper. Slowly whisk in the olive oil; whisk until the mixture is emulsified.

Step 3

Place the tenderloin into a resealable bag and pour the marinade over it. Refrigerate for 8 hours, or overnight.

Step 4

When ready to cook, set Traeger to 450°F and preheat, lid closed, for 15 minutes.

Step 5

Remove the tenderloins from the marinade (discard the marinade) and pat dry. Knock off any pieces of garlic or rosemary. Season generously with black pepper and less generously with coarse salt.

Step 6

Arrange the tenderloins at a diagonal to the grill grate and sear, turning with tongs as needed, until well-browned on all sides, about 3 to 4 minutes per side.

Step 7

Continue to cook until the tenderloins reach your desired degree of doneness, about 15 to 20 minutes total for medium-rare, 135°F on a meat thermometer.

Step 8

Let the meat rest for 5 minutes before slicing on a diagonal. Garnish with rosemary sprigs, if desired. Enjoy!