Serves 4 to 6
Two tablespoons of chopped fresh parsely leaves may be substituted for the tarragon in this recipe.
2 pounds boneless, skinless chicken breasts, thighs or a combination
Salt and pepper
1 tablespoon unsalted butter
1 tablespoon olive oil
1 pound cremini mushrooms, trimmed and cut into 1/4-inch slices
1 onion, chopped fine
1/4 cup dry white wine
1 tablespoon all-purpose flour
1 garlic clove, minced
1 1/2 cups low-sodium chicken broth
1/2 cup sour cream
1 egg yolk
1 teaspoon freshly grated nutmeg
2 teaspoons juice from 1 lemon
2 teaspoons minced fresh tarragon
Pat chicken dry with paper towels and season with 1 teaspoon salt and 1/2 teaspoon pepper. Heat butter and oil in 12-inch skillet over medium-high heat. When foaming subsides, place chicken in skillet and continue to cook until browned, about 4 minutes. Flip chicken and continue to cook until browned on second side, about 4 minutes longer. Transfer chicken to large plate.
Add mushrooms, onion and wine to now-empty skillet and cook, stirring occasionally, until liquid has evaporated and mushrooms are browned, 8 to 10 minutes. Add flour and garlic; cook, stirring constantly, 1 minute. Add broth and bring mixture to boil, scraping up any browned bits. Add chicken and any accumulated juices to skillet. Reduce heat to medium-low, cover, and simmer until breasts register 160 degrees and thighs register 175 degrees, 5 to 10 minutes.
Transfer chicken to clean platter and tent loosely with foil. Whisk sour cream and egg yolk together in medium bowl. Whisking constantly, slowly stir 1/2 cup sauce into sour cream mixture. Stirring constantly, slowly pour sour cream mixture into simmering sauce. Stir in nutmeg, lemon juice, and tarragon; return to simmer. Season to taste with salt and pepper. Pour sauce over chicken and serve.