Turkey Tenderloin with Whiskey-Cherry Sauce

Preheat oven to 450°F. Heat 2 teaspoons oil in a large ovenproof skillet over high heat. Season turkey with 1/4 teaspoon salt and pepper and cook until golden brown on one side, about 3 minutes. Turn it over and transfer the pan to the oven. Roast until the turkey is no longer pink in the middle and registers 165°F on an instant-read thermometer, 15 to 20 minutes. Transfer the turkey to a clean cutting board and tent with foil to keep warm. Heat the remaining 1 teaspoon oil in the pan over medium-high heat. (Be careful, the handle will still be hot.) Add onion and cook, stirring, until starting to soften, 2 to 3 minutes. Add garlic and cook, stirring, for 30 seconds. Add cherries, 3/4 cup cranberry juice, whiskey, thyme, mustard and the remaining 1/4 teaspoon salt. Cook, stirring occasionally and scraping up any browned bits, until reduced, about 4 minutes. Meanwhile, stir together the remaining 1/4 cup juice and cornstarch in a small bowl. Add to the pan and cook, stirring, until thickened, about 30 seconds. Slice the turkey and serve with the sauce.