PreparationFor plum chutney: Peel plums, if desired. Halve and pit. Cut into 1/2" wedges. Heat oil in a medium saucepan over medium heat. Add shallot and cook, stirring occasionally, until shallot begins to soften, about 2 minutes. Add brown sugar, next 6 ingredients, and 1/4 cup water. Cook, stirring occasionally, until mixture is fragrant, about 2 minutes. Stir in plums. Cover and simmer over medium heat, stirring occasionally, for 8 minutes. Uncover and continue cooking, stirring occasionally, until fruit is soft and juices have thickened, 20-25 minutes. Season to taste with salt. Let cool slightly. DO AHEAD: Chutney can be made 1 week ahead. Cover and chill. Rewarm slightly before serving. For pork: Stir rosemary, herbes de Provence, and oil in a small bowl. Rub all over pork; season with salt and pepper. Wrap pancetta slices around pork and tie at 2" intervals with kitchen twine to hold together. DO AHEAD: Can be made 1 day ahead. Cover and chill. If using a charcoal grill, build a medium-hot fire; push coals over to 1 side of grill. If using a gas grill, heat all but 1 burner to high. Grill tenderloins over hot part of grill, turning frequently, until a crisp brown crust forms on all sides, 8-10 minutes. Move tenderloins to cooler part of grill to gently cook through; cover and cook until an instant-read thermometer inserted into the middle of each loin registers 145°F, 15-20 minutes longer. Transfer tenderloins to a cutting board. Let rest for 10 minutes. Slice thinly and serve with plum chutney alongside.
PreparationFor plum chutney: Peel plums, if desired. Halve and pit. Cut into 1/2" wedges. Heat oil in a medium saucepan over medium heat. Add shallot and cook, stirring occasionally, until shallot begins to soften, about 2 minutes. Add brown sugar, next 6 ingredients, and 1/4 cup water. Cook, stirring occasionally, until mixture is fragrant, about 2 minutes. Stir in plums. Cover and simmer over medium heat, stirring occasionally, for 8 minutes. Uncover and continue cooking, stirring occasionally, until fruit is soft and juices have thickened, 20-25 minutes. Season to taste with salt. Let cool slightly. DO AHEAD: Chutney can be made 1 week ahead. Cover and chill. Rewarm slightly before serving. For pork: Stir rosemary, herbes de Provence, and oil in a small bowl. Rub all over pork; season with salt and pepper. Wrap pancetta slices around pork and tie at 2" intervals with kitchen twine to hold together. DO AHEAD: Can be made 1 day ahead. Cover and chill. If using a charcoal grill, build a medium-hot fire; push coals over to 1 side of grill. If using a gas grill, heat all but 1 burner to high. Grill tenderloins over hot part of grill, turning frequently, until a crisp brown crust forms on all sides, 8-10 minutes. Move tenderloins to cooler part of grill to gently cook through; cover and cook until an instant-read thermometer inserted into the middle of each loin registers 145°F, 15-20 minutes longer. Transfer tenderloins to a cutting board. Let rest for 10 minutes. Slice thinly and serve with plum chutney alongside.