Pat chicken dry and pound to even 3/4-inch thickness. Season both sides with salt, pepper, and 1 tsp Italian seasoning.
Heat oil in skillet over medium-high heat. Sear chicken 5-6 minutes per side until golden and cooked through (165°F internal temp). Remove to plate.
Reduce heat to medium. Add garlic and cook 30 seconds until fragrant.
Pour in chicken broth, scraping up brown bits. Add sun-dried tomatoes and remaining 1 tsp Italian seasoning. Simmer 2 minutes.
Reduce heat to low. Stir in heavy cream, Greek yogurt, and Parmesan until smooth and creamy.
Return chicken to pan, spoon sauce over top, and simmer 3-4 minutes. Garnish with fresh basil and serve.