In a large skillet, heat the oil or butter over medium heat. Add the onion and sauté for 2-3 minutes, until softened.
Add the mushrooms and cook another 5-6 minutes until they have cooked down.
Add the garlic and ground turkey and cook until the turkey is no longer pink, about 8 minutes.
Add the salt, pepper, thyme, paprika, and flour to the turkey mixture and stir to combine.
Stir in the broth, Dijon mustard, Worcestershire sauce, tomato paste ,and milk and bring the mixture to a simmer. Allow to simmer, stirring occasionally, until the sauce thickens, about 3-5 minutes.
Meanwhile, cook the egg noodles according to the package directions.
Stir the Greek yogurt into the turkey mixture and cook until heated through, another minute.