Pat the chicken dry and season both sides with salt and pepper.
Heat olive oil in a large skillet over medium-high heat. Sear the chicken for 5 to 6 minutes per side, until golden brown and cooked through. Transfer to a plate.
Lower the heat to medium and add the garlic to the same skillet, stirring for about 30 seconds until fragrant.
Whisk in the chicken broth, scraping up the browned bits from the bottom of the pan, then stir in the heavy cream, Parmesan, sun-dried tomatoes, Italian seasoning, and red pepper flakes.
Simmer for 3 to 4 minutes, stirring occasionally, until the sauce thickens slightly.
Return the chicken to the skillet, spoon the sauce over the top, and simmer for 2 more minutes to warm through.
Stir in the fresh basil and serve immediately.