Season chicken breasts on both sides with salt and black pepper.
Heat olive oil in a large skillet over medium heat. Add chicken and sear for 4–5 minutes per side until golden. Remove and set aside.
In the same skillet, melt butter and add minced garlic. Cook for 30 seconds until fragrant.
Stir in sun-dried tomatoes and cook for 1–2 minutes.
Pour in chicken broth and heavy cream. Stir and bring to a gentle simmer.
Reduce heat to low and add parmesan cheese, Italian seasoning, and red pepper flakes if using. Stir until smooth.
Return chicken to the skillet and spoon sauce over the top.
Simmer for 8–10 minutes until chicken is cooked through and sauce is thick and creamy.
Garnish with fresh basil if desired and serve hot.
