01 - Bring a large pot of salted water to a rolling boil. Add the cheese tortellini and cook according to package directions until al dente. Drain well and set aside.
02 - While the tortellini cooks, season the diced chicken breasts generously with salt, pepper, and Italian seasoning. Heat olive oil in a large skillet over medium-high heat. Add the seasoned chicken in a single layer and cook for 5–7 minutes, turning once, until golden brown and cooked through. Transfer the chicken to a plate and set aside.
03 - In the same skillet, reduce heat to medium and melt the butter. Add the chopped onion and sauté for 2–3 minutes until softened and translucent. Stir in the minced garlic and cook for 1 minute until fragrant, being careful not to let it brown.
04 - Pour in the chicken broth to deglaze the pan, scraping up any browned bits from the bottom. Stir in the heavy cream and grated Parmesan cheese. Continue stirring for about 3 minutes until the cheese has fully melted and the sauce thickens slightly.
05 - Add the fresh baby spinach to the skillet and gently stir into the sauce for 1–2 minutes until just wilted.
06 - Return the seared chicken to the skillet along with the drained tortellini. Gently toss everything together until evenly coated in the creamy garlic sauce. Taste and adjust seasoning with additional salt and pepper if needed. Serve immediately, garnished with extra Parmesan and chopped fresh parsley.