Heat the olive oil in a large skillet over medium-high heat.
Add the chicken pieces and cook for 3-4 minutes per side until browned.
Remove the chicken from the skillet and set aside.
Add the onion to the skillet and cook for 2-3 minutes until translucent.
Add the mushrooms and garlic and cook for 2-3 minutes more.
Stir in the Dijon mustard, chicken broth, sour cream, Worcestershire sauce, and paprika.
Return the chicken to the skillet and simmer for 15-20 minutes until the chicken is cooked through.
Season with salt and pepper to taste.
Garnish with chopped parsley if desired.
