• 4 Tsp.s extra-virgin olive oil, divided
  • 1 ½ C thinly sliced red onion
  • 2 Tsp.s minced fresh rosemary, divided
  • 1/8 Tsp. salt
  • Freshly ground pepper to taste
  • 2/3 C shredded fontina cheese, preferably aged
  • 4 boneless, skinless chicken breasts (about 1 pound), trimmed of fat
  • ½ C white wine
  • 1 C reduced-sodium chicken broth
  • 4 Tsp.s all-purpose flour
  1. Heat 2 teaspoons oil in a large nonstick skillet over medium-high heat. Add onion and 1 teaspoon rosemary; cook, stirring occasionally, until the onion is golden brown, 6 to 7 minutes. Season with salt and pepper. Let cool; stir in fontina.
  2. Meanwhile, cut a horizontal slit along the thin, long edge of each chicken breast half, nearly through to the opposite side. Stuff each breast with 1/4 cup of the onion-cheese mixture.
  3. Heat the remaining 2 teaspoons oil in the same skillet over medium-high heat. Add the chicken and cook until golden, about 5 minutes per side. Transfer to a plate and cover with foil to keep warm.
  4. 4. Add wine and the remaining 1 teaspoon rosemary to the pan. Cook over medium-high heat for 2 minutes. Whisk broth and flour in a bowl until smooth; add to the pan, reduce heat to low and whisk until the sauce thickens, about 1 minute. Return the chicken to the pan and coat with the sauce. Cook, covered, until the chicken is just cooked through, 2 to 4 minutes. Serve the chicken topped with the sauce.