Begin by cutting boneless, skinless chicken breasts into bite-sized pieces, seasoning them with garlic powder, salt, and pepper. Dredge the chicken in flour and set aside.

Heat 2 tablespoons of olive oil in a large skillet over medium-high heat. Add the dredged chicken in batches, cooking for about 3 minutes per side until golden brown. Transfer the browned chicken to a plate.

In the same skillet, melt 2 tablespoons of butter over medium heat. Add sliced cremini mushrooms and chopped onions, sautéing for 6 to 8 minutes until the mushrooms are tender.

Stir in 1 tablespoon of Dijon mustard, 1 tablespoon of Worcestershire sauce, and 2 minced garlic cloves. Cook for 1 minute until fragrant.

Pour in 1 cup of chicken broth while scraping up browned bits from the bottom. Return the cooked chicken to the skillet and simmer for 2 minutes.

Lower the heat and add 1 cup of sour cream, stirring gently to combine without boiling. Adjust seasoning with salt and pepper.

Remove from heat and serve immediately. Pairs well with egg noodles, rice, or crusty bread.