Pat the chicken breasts dry, then season both sides with salt and black pepper. Lightly dredge in flour, shaking off any excess.
Heat olive oil in a large pan over medium-high heat. Add the chicken and cook undisturbed for 5–7 minutes per side until golden brown and cooked through. Remove from the pan and set aside.
Reduce the heat to medium. Add the minced garlic to the same pan and cook for about 30 seconds until fragrant, being careful not to brown it.
Pour in the heavy cream and chicken broth, stirring to deglaze the pan and lift any browned bits from the bottom.
Add the sun-dried tomatoes, grated parmesan, Italian seasoning, and chili flakes if using. Let the sauce simmer for 3–4 minutes, stirring occasionally, until slightly thickened.
Return the chicken to the pan and spoon the sauce over the top. Let it simmer gently for 2–3 minutes so the flavors come together.
Finish with fresh basil, taste and adjust seasoning if needed, and serve warm with extra sauce.