2 tablespoons olive oil
1 onion, thinly sliced into rings or crescents
1 1/2 teaspoons kosher salt
1/2 teaspoon freshly ground black pepper
8 ounces (15 medium) button mushrooms, thinly sliced
2 boneless, skinless chicken breasts, cut into 1/2-inch-thick strips
1/2 cup white cooking wine
3/4 cup chicken broth
1+ tablespoon Worcestershire sauce
2 teaspoons Dijon mustard
1/4 - 1/2 cup sour cream (depending on how creamy and saucy you like it)
1. Heat 1 tablespoon of the oil in a large saucepan over medium heat. Add the onions and cook, stirring frequently, until soft, about 8 minutes. Add the mushrooms, 1/2 teaspoon of the salt, 1/4 teaspoon of the pepper, and continue cooking until the mushrooms give up their liquid, about 6 minutes, and are tender. Set veggies aside in a medium bowl.
2. Return pan to heat and add the remaining 1 tablespoon of oil. Season the chicken with the remaining 1 teaspoon of salt and 1/4 teaspoon of pepper. Cook the chicken until golden brown and cooked through. Add it to the vegetables.
3. Pour the wine and broth into the pan and bring to a boil. With a wooden spoon, loosen any brown bits stuck to the pan and let cook in the sauce. Add the Worcestershire (add more than the 1 tablespoon if you are big fans), and mustard. Whisk until smooth. Boil until the liquid has reduced by just less than half.
4. Remove from heat and whisk in the sour cream. Do not let the sauce boil after adding the cream. Return the vegetables and chicken to the pan and heat through. Serve over rice, pasta, or toast.
Adapted from Real Simple, photo from Real Simple.com (photo shows Stroganoff made with green peppers, which, frankly I cannot endorse).