Start by laying your chicken breasts flat in a zip-top bag or between two sheets of plastic wrap. Use a meat mallet or rolling pin to pound them evenly to about ½-inch thick. This ensures even, quick cooking. Season both sides generously with kosher salt and black pepper.

Heat olive oil in a large skillet over medium-high heat. Place the chicken breasts in the skillet and sear them for about 5–7 minutes per side, until golden brown and cooked through. Transfer the chicken to a plate, but don’t clean the skillet—that’s where all the flavor is!

Reduce the heat to medium. Add the unsalted butter to the skillet and melt it, scraping up any browned bits from the chicken. Toss in the diced shallots and garlic, cooking gently until they’re soft and fragrant. This will create the base of your mouthwatering sauce.

Pour in the half-and-half and chicken broth, stirring as you go. Bring the mixture to a simmer while scraping the skillet to deglaze it. Gradually stir in the Parmesan cheese, allowing it to melt completely into the sauce. The result should be a creamy, velvety sauce with a hint of garlic and cheese.

Return the cooked chicken to the skillet, nestling it into the sauce. Spoon the sauce over each piece to coat it evenly. Simmer for an additional 2–3 minutes to ensure the chicken absorbs the flavors and the sauce thickens slightly. Sprinkle chopped parsley over the dish just before serving to add a pop of freshness.