Line a plate with paper towels. Set aside.
Place flour in a shallow bowl or pie plate. Set aside.
1 cup all-purpose flour
Cut each chicken breast in half horizontally, for a total of 4 pieces of chicken. Use a meat mallet to pound each breast to an even ½-inch thickness. Season the chicken with salt and pepper.
Dredge each chicken breast in the flour, coat all sides, and shake off any excess.
2 boneless, skinless chicken breasts, Kosher salt and freshly ground black pepper
Melt 2 tablespoons of butter with 3 tablespoons of olive oil in a large skillet set over medium-high heat. Once sizzling, add 2 chicken breasts and cook for 3 minutes per side, until browned. Transfer to the prepared plate and repeat with remaining 2 chicken breasts.
6 tablespoons unsalted butter, 5 tablespoons olive oil
To the empty skillet, add the onion and garlic and sauté until fragrant, about 1-2 minutes.
¼ cup diced onion, 4 cloves garlic
Stir in the wine to deglaze the skillet. Allow the wine to reduce for 1 minute, then add the chicken broth, lemon juice and zest, and capers.
¼ cup white wine, ¾ cup low sodium chicken broth, 1 lemon, 3 tablespoons capers
Bring the mixture to a low boil. Add the remaining butter and whisk vigorously until melted.
Return the chicken to the skillet and simmer until warmed through, about 5 minutes. Serve chicken and sauce over pasta and garnish with parsley.
Chopped fresh parsley, 8 ounces cooked pasta