Dice the chicken into 1-inch pieces and season with garlic powder, salt and pepper to taste. Dredge the chicken in flour.
Heat olive oil in a large Dutch oven over medium-high heat. Cook the chicken in batches, being careful not to over crowd the pan so that the chicken will brown properly. Remove chicken to a bowl.
Note: you can also use pre-cooked rotisserie chicken in this recipe for a quick meal.
Deglaze the pan with chicken broth and then add Dijon mustard and Worcestershire sauce. Add back the chicken and simmer for a couple minutes until the chicken is heated through.
Stir in the sour cream and heat gently being careful that the sour cream does not curdle. Taste and season with salt and pepper as needed.