Season chicken pieces with garlic powder, salt, and pepper. Dredge in flour.
Cook chicken in batches until browned and fully cooked. Set aside.
Cook mushrooms and onions until browned and liquids evaporate.
Add Dijon, Worcestershire, and garlic. Cook briefly.
Pour in chicken broth, scraping up flavorful bits. Return chicken to the skillet.
Stir in sour cream until well combined. Season with salt and pepper.
Enjoy this delightful dish over egg noodles, mashed potatoes, or rice.