Season chicken breasts on both sides with salt, pepper, and Italian seasoning. Pound to even 3/4-inch thickness if needed.
Heat sun-dried tomato oil in a large skillet over medium-high heat until shimmering. Add chicken and sear undisturbed for 5-6 minutes until golden brown.
Flip chicken and cook another 5-6 minutes until internal temperature reaches 165°F. Remove to a plate and tent with foil.
In the same skillet, add minced garlic and chopped sun-dried tomatoes. Sauté for 1 minute until fragrant.
Pour in chicken broth to deglaze, scraping up browned bits. Add heavy cream, parmesan cheese, and red pepper flakes. Whisk and simmer 3-4 minutes until sauce thickens.
Stir in fresh spinach and let wilt for 1-2 minutes. Return chicken to skillet, spoon sauce over each piece, and heat through for 2-3 minutes.
Garnish with fresh basil and serve immediately while sauce is creamy and warm.