In casserole dish large enough to accommodate chicken, combine yogurt, olive oil, garlic, sage, rosemary, thyme, parsley, paprika, pepper, and salt. Add chicken and rub with marinade on all sides. Place breast side up, cover and refrigerate for 4 hours.

When ready to cook, preheat oven to 425 F . Remove chicken from refrigerator, place on parchment-lined baking sheet to come to room temperature while oven heats. Roast in preheated oven for 40 to 45 minutes, or until chicken reaches an internal temperature of 165 F. Alternately, heat outdoor grill to 400 F . Grill chicken breast side down over direct heat, with lid closed, for 5 to 10 minutes. Flip chicken, turn burner off, and keep lid closed. Roast for 40 to 45 minutes. Once cooked, remove chicken to cutting board and allow to rest, covered, for 20 minutes.

While chicken rests, make plum drizzle. In bowl of food processor, add plums, serrano pepper, tomato paste, and vinegar. Blitz until smooth. Add honey and salt. Just prior to serving, heat gently on low heat, until just warm.

Cut chicken into pieces to provide variety and make it easier for guests to serve themselves. Remove wings. Remove and separate breasts and slice into several pieces. Remove leg from thighs. Arrange the pieces on family-style platter and drizzle with sauce.