Pat chicken breast pieces completely dry with paper towels to ensure a crisp golden sear. Season thoroughly on all sides with kosher salt, freshly cracked black pepper, and Italian seasoning.

Heat 2 tablespoons of oil from the sun-dried tomato jar in a large 6-quart enameled Dutch oven or heavy-bottomed soup pot over medium-high heat. Add chicken pieces in a single layer without overcrowding. Sear undisturbed for 3 to 4 minutes until deeply golden on the bottom, then flip and cook for an additional 2 minutes until just cooked through. Transfer the seared chicken to a clean plate and set aside.

Reduce the stovetop heat to medium. Melt the unsalted butter directly into the pan drippings. Add the minced garlic and julienned sun-dried tomatoes, stirring continuously for 60 to 90 seconds until fragrant and aromatic (do not burn the garlic).

Sprinkle the flour over the aromatics and stir vigorously for 1 minute to cook out the raw flour taste and form a smooth roux paste with the fond.

Slowly pour in the chicken bone broth while whisking constantly with a wooden spoon, scraping up every flavorful caramelized browned bit from the bottom of the pot. Bring the liquid to a gentle, steady simmer for 5 minutes.

Add the refrigerated cheese tortellini directly into the simmering broth. Cook uncovered for 3 to 4 minutes just until tender and floating (avoid overboiling to preserve the delicate pasta structure).

Reduce heat to low. Slowly stir in the heavy cream and return the seared chicken bites along with any collected resting juices back into the Dutch oven. Stir gently to integrate.

Add the fresh baby spinach and stir for 60 seconds until gently wilted into the cream broth. Turn off the stovetop heat and whisk in the freshly grated Parmigiano-Reggiano cheese until completely melted and velvety smooth. Season with crushed red pepper flakes and torn fresh basil.

Ladle into warm wide ceramic bowls. Top with extra shaved parmesan ribbons, cracked black pepper, and serve immediately alongside warm crusty sourdough bread.