4 boneless skinless chicken breasts, trimmed of fat
1 tsp kosher salt, divided
1/4 cup, plus 1 tablespoon all-purpose flour, divided
3 teaspoons extra virgin olive oil, divided
2 large shallots, finely chopped
1/2 cup dry white wine
1 14 oz can reduced-sodium chicken broth
1/3 cup reduced fat sour cream
1 tablespoon dijon mustard
1/2 cup chopped chives
Place chicken between sheets of plastic wrap and pound until flattened to an even thickness, about 1/2 inch. Season both sides with salt, dividing 1/2 a teaspoon amongest all the chicken. Place 1/4 cup flour in a shallow glass baking dish and dredge the chicken in it. Discard the excess flour.
Heat 2 tsp oil in a large nonstick skillet over medium high heat. Add the chicken and cook until golden brown, 1 to 2 minutes per side. Transfer to a plate, cover and keep warm.
Heat the remaining 1 teaspoon oil in the pan over medium-high heat. Add shallots and cook, stirring constantly and scraping up any brown bits, untl golden brown, 1 to 2 minutes. Sprinkle with the remaining 1 tablespoon flour, stir to coat. Add wine, broth and remaining 1/2 tsp salt, bring to a boil, stirring often.
Return the chicken and any accumulated juices to the pan, reduce the heat to a simmer and cook until heated through and no longer pink in the center, about 6 minutes. Stir in sour cream and mustard until smooth, turn the chicken to coat with the sauce. Stir in chives and serve immediately.