Prep the Chicken: Cut chicken into bite-sized pieces. Season with salt, pepper, and garlic powder, then lightly dredge in flour, shaking off the excess.
Sear the Chicken: Heat 2 tablespoons of olive oil in a large skillet over medium-high heat. Cook the chicken in two batches until golden brown and fully cooked (about 3 minutes per side). Set aside.
Cook the Veggies: In the same skillet, add 1 tablespoon olive oil and a tablespoon of butter. Sauté the mushrooms and onions for 6–8 minutes until browned and their moisture has evaporated.
Add Flavor: Stir in garlic, Dijon mustard, and Worcestershire sauce. Cook for another minute to bring out the flavors.
Deglaze and Simmer: Pour in the chicken broth, scraping up all the tasty browned bits from the pan. Return the chicken to the skillet and simmer for 2–3 minutes.
Creamy Finish: Remove from heat and stir in sour cream until fully incorporated. Season with additional salt and pepper to taste.
Serve: Ladle over warm egg noodles, mashed potatoes, or rice. Garnish with chopped parsley or a dollop of sour cream, if desired.
