Turchetta Meatballs with Gravy Dipper

Name: Turchetta Meatballs with Gravy Dipper
Ingredients: 2 Tbs. extra-virgin olive oil; 1/2 yellow onion, cut into small dice; 2 garlic cloves, minced; 3 Tbs. Turchetta Turkey Rub; 1/2 lb. (250 g) ground pork; 1/2 lb. (250 g) ground dark meat turkey; 3 Tbs. panko; 2 tsp. Worcestershire sauce; 1 egg; 16 thin slices prosciutto; 3 Tbs. neutral oil; Fried sage leaves and rosemary sprigs for garnish; Kosher salt; 1 cup (8 fl. oz./250 ml) warm gravy, prepared with Williams Sonoma Turkey Gravy Base according to packaging instructions