01 - Preheat oven to 400°F. Line a baking sheet with parchment paper.
02 - In a large bowl, combine ground turkey, breadcrumbs, milk, egg, parsley, garlic, onion powder, salt, and pepper. Mix until just combined.
03 - With damp hands, form the mixture into 20–24 small meatballs and place on the prepared baking sheet.
04 - Bake meatballs for 15–18 minutes, or until cooked through and lightly golden.
05 - While meatballs bake, heat olive oil in a large skillet over medium heat. Add mushrooms and onion; sauté for 5–7 minutes until softened and lightly browned.
06 - Add garlic and cook for 1 minute. Sprinkle flour over the vegetables and stir for 1–2 minutes to coat.
07 - Gradually whisk in chicken broth, Worcestershire sauce, and Dijon mustard. Simmer for 3–4 minutes, stirring, until slightly thickened.
08 - Reduce heat to low. Stir in sour cream until smooth. Season with salt and pepper.
09 - Gently add baked meatballs to the sauce, spooning sauce over to coat. Simmer for 2–3 minutes to heat through.
10 - Serve meatballs and sauce over cooked egg noodles. Garnish with fresh parsley.