Pat chicken dry, cut into bite-size pieces, and season with salt, pepper, and Italian seasoning.
Heat olive oil in a large skillet over medium-high heat and cook chicken until golden and cooked through, 6-8 minutes.
Remove chicken and set aside.
Lower heat to medium, add butter, then sauté garlic and red pepper flakes for 30 seconds until fragrant.
Stir in chicken broth, heavy cream, Italian seasoning, and sun-dried tomatoes.
Bring to a gentle simmer and whisk in Parmesan cheese until melted and smooth.
Add cooked chicken and fresh tortellini to the sauce.
Cook uncovered, stirring occasionally, for 5 minutes until tortellini is tender and sauce has thickened.
Garnish with fresh basil and serve.