Add olive oil to a large skillet and place over medium-high heat. Add chicken and season with ½ teaspoon salt. Cook about 5 minutes, stirring occasionally. Add minced garlic and continue to cook until chicken starts to brown about 4 minutes.
Add mushrooms and continue to cook, stirring occasionally until chicken is lightly browned and mushrooms become soft, about 5 minutes.
Add chicken broth and Greek yogurt and lower to simmer.
Mix milk and cornstarch together and add to chicken mixture. Add Worcestershire, Dijon mustard and fresh thyme. Cook for 20 minutes or until sauce has thickened.
Serve over egg noodles.