Ingredients:
4 boneless, skinless chicken breast halves, (1-1 1/4 pounds)
1/4 cup all-purpose flour
1/2 teaspoon salt, or to taste
Freshly ground pepper, to taste
1 tablespoon extra-virgin olive oil, or canola oil
1/2 pound cremini, or baby bella mushrooms, wiped clean and thinly sliced (2 1/2 cups)
1 small leek, trimmed, washed (see Tip) and thinly sliced (3/4 cup)
1/2 cup dry white wine, or vermouth
3/4 cup reduced-sodium chicken broth
1 teaspoon cornstarch
1/3 cup reduced-fat sour cream
3/4 teaspoon Dijon mustard
1/8 teaspoon salt, or to taste
Freshly ground pepper, to taste
2 tablespoons chopped fresh parsley
Directions:
1.Trim visible fat from chicken breasts. Remove the tenders (the long thin flaps); reserve for another use (see Tip). Place trimmed chicken breasts between 2 pieces of plastic wrap. Pound with a rolling pin, meat mallet or heavy skillet until flattened to an even thickness, about 1/2 inch. Combine flour, salt and pepper in a shallow glass dish. Dredge chicken in seasoned flour, shaking off excess. (Discard any leftover flour.)
2.Heat oil in a large nonstick skillet over medium-high heat. Add the chicken and cook until well browned and no longer pink in the center, 4 to 5 minutes per side. Transfer to a plate, cover and keep warm.
3.Add mushrooms and leek to the pan; cook over medium heat, stirring often, until most of the moisture has evaporated and the mushrooms are beginning to brown, 4 to 6 minutes. Add wine (or vermouth) and deglaze, scraping up any browned bits, for about 1 minute. Mix broth and cornstarch in a small bowl. Add to the pan and cook until thickened, 2 to 3 minutes. Stir in sour cream and mustard; cook until heated through, about 1 minute. Season with salt and pepper. Spoon over the chicken and sprinkle with parsley.
