01 - Season chicken strips thoroughly with salt and pepper on all sides.
02 - Heat 1 tbsp butter and olive oil in a large skillet over medium-high heat. Add chicken and sauté until golden brown and cooked through, approximately 5–7 minutes. Transfer to a plate and reserve.
03 - Add remaining 1 tbsp butter to the same pan. Sauté onion for 2–3 minutes until translucent. Add mushrooms and cook until browned and liquid has evaporated, about 5 minutes. Stir in garlic and cook for 1 minute until fragrant.
04 - Sprinkle flour over vegetables, stirring constantly to coat evenly. Cook for 1 minute to remove raw flour taste.
05 - Gradually pour in chicken broth while stirring continuously. Add Dijon mustard, paprika, and Worcestershire sauce. Simmer for 3–4 minutes until sauce thickens slightly.
06 - Reduce heat to low. Stir in sour cream until fully incorporated—avoid boiling to prevent curdling. Return chicken and accumulated juices to the skillet. Simmer gently for 2–3 minutes until heated through.
07 - Taste sauce and adjust seasoning with additional salt and pepper if needed.
08 - Garnish generously with fresh parsley. Serve immediately over egg noodles, rice, or mashed potatoes.