In a large pot, bring salted water to a boil. Add the cheese tortellini and cook according to package instructions until al dente, usually about 3-5 minutes. Drain and set aside.
In a large skillet, heat the olive oil over medium heat. Add the diced chicken, season with salt, pepper, and Italian seasoning. Cook until the chicken is golden brown and cooked through, about 6-8 minutes.
Once the chicken is cooked, add the minced garlic to the skillet. Sauté for an additional 1-2 minutes until fragrant.
Reduce the heat to low, then pour in the heavy cream, stirring well to combine. Gradually add the grated Parmesan cheese, stirring continuously until melted and creamy.
Add the cooked tortellini and chopped spinach into the skillet. Toss everything together until the spinach is wilted and the tortellini is fully coated in the creamy sauce.
Taste and adjust seasoning with more salt and pepper if desired. Serve hot, garnished with freshly chopped parsley on top.