Preheat your oven to 400°F. In a small skillet, heat 1 tablespoon olive oil over medium heat. Add the minced onion and garlic. Sauté for about 5 minutes until softened. Set aside to cool before adding to the meatball mixture.
In a bowl, combine ground turkey, breadcrumbs, beaten egg, 1/2 tablespoon Worcestershire sauce, dried parsley, allspice, nutmeg, salt, pepper, and the cooled onion and garlic. Gently mix until just combined and form into 1-inch balls.
Place the meatballs on a lightly greased baking dish and bake in the preheated oven for about 13-18 minutes, or until they reach an internal temperature of 165°F.
In a large skillet, heat the remaining olive oil over medium heat. Sprinkle in the flour and stir for 1 minute to form a roux. Gradually whisk in the chicken broth and cook until the sauce thickens, about 3 minutes.
Add the remaining Worcestershire sauce and the Dijon mustard. Season the sauce to taste with salt and pepper.
Lower the heat and stir in the sour cream. Add the baked meatballs to the sauce and simmer for 5-10 minutes to blend the flavors. Serve hot, garnished with parsley. Enjoy over egg noodles or with mashed potatoes.