Season the chicken breasts on both sides with salt, pepper, and garlic powder.

In a large skillet over medium-high heat, add olive oil. Sear chicken breasts for about 5–6 minutes per side, or until golden brown and cooked through. Remove from the pan and set aside.

In the same skillet, reduce heat to medium. Add minced garlic and sauté for 1 minute. Stir in chicken broth and heavy cream. Let simmer for 2–3 minutes.

Stir in Parmesan and mozzarella cheese, mixing until melted and smooth. If you'd like a thicker sauce, add the cornstarch slurry here.

Stir in fresh basil and let everything simmer for another minute.

Return the chicken to the skillet. Spoon the sauce over each piece and let it cook for 2–3 more minutes until everything is heated through and cheese is bubbly.

Serve hot, with extra sauce spooned over the top.