Mix together salt, garlic powder, onion powder, and black pepper.
Season chicken breasts on both sides with the prepared mix.
Heat skillet over medium-high heat, add olive oil and butter, and sear chicken until golden brown, not fully cooked.
In a bowl, whisk chicken broth and cornstarch until smooth.
Pour the broth mixture into an 8-quart slow cooker.
Whisk in heavy cream, garlic powder, Italian seasoning, salt, black pepper, red pepper flakes, and paprika.
Place seared chicken in the slow cooker and pour oil and butter from the skillet over it.
Top with chopped sun-dried tomatoes.
Cover and cook on low for 6–7 hours.
Remove chicken and whisk in Parmesan cheese until the sauce is smooth.
Return chicken to the cooker, spoon sauce over it, and sprinkle with chopped fresh basil.
Serve warm.