Slice each chicken breast in half lengthwise to make thinner cutlets. Season both sides with salt and freshly ground black pepper.
Heat the oil in a large skillet over medium-high heat.
Add the chicken to the hot skillet and sear for 5–6 minutes per side, or until golden brown and fully cooked (internal temperature should reach 165°F / 74°C). Transfer the chicken to a plate and set aside.
In the same skillet, add the minced garlic and red chili flakes. Sauté for about 30 seconds, just until fragrant.
Pour in the tomato sauce and half & half. Stir well, bring to a gentle simmer, and let it cook for 2 minutes to blend the flavors.
Add the grated Parmesan and chopped kale. Cook for 2–3 minutes, stirring occasionally, until the kale is wilted and the sauce is creamy.
Return the chicken to the skillet, spoon some sauce over the top, and cook for another minute to heat through.
Garnish with fresh basil leaves and extra Parmesan if desired. Serve warm and enjoy!