Preheat oven to 300 degrees F (150 degrees C). Combine chopped parsley, vinegar, fresh lemon juice, garlic, honey, red pepper flakes, and salt in a large bowl. Mix well and set aside. Whisk olive oil, salt, cumin, black pepper, dried Italian herbs, cinnamon, coriander, and paprika in a large bowl until combined. Coat each lamb breasts in the olive oil and spice mixture and transfer to a roasting pan, fat side up. Tightly cover roasting pan with aluminum foil and bake in the preheated oven until the meat is tender when pierced with a fork, about 2 hours. Remove lamb from oven and cut into four pieces. Increase oven temperature to 450 degrees F (230 degrees C). Line a baking sheet with aluminum foil and place lamb pieces on it. Brush the tops of each piece with fat drippings from the roasting pan. Bake lamb until meat is browned and edges are crispy, about 20 minutes. Increase the oven's broiler to high and brown lamb for 4 minutes. Remove from oven. Serve lamb topped with parsley and vinegar sauce.