Cook the Tortellini: If using frozen tortellini, cook according to package directions. If using fresh tortellini, cook until al dente, usually 3-5 minutes. Drain and set aside.

Sauté the Chicken (if using): In a large skillet or Dutch oven, heat olive oil over medium-high heat. Add chicken and cook until browned and cooked through, about 5-7 minutes. Season with salt and pepper. Remove chicken from the skillet and set aside.

Sauté Aromatics: Reduce heat to medium. Add garlic and sun-dried tomatoes to the skillet and cook until fragrant, about 1 minute. Add red pepper flakes and stir.

Create the Sauce: Pour in chicken broth and bring to a simmer, scraping up any browned bits from the bottom of the pan. Stir in heavy cream and Parmesan cheese. Reduce heat to low and simmer, stirring occasionally, until the sauce has thickened slightly, about 5-7 minutes.

Combine: Add the cooked tortellini and chicken (if using) to the sauce. Toss to coat. Stir in fresh basil.

Serve: Season with salt and pepper to taste. Serve immediately, garnished with additional Parmesan cheese and fresh basil.