01 - Bring a large pot of salted water to a rolling boil. Cook the cheese tortellini according to the package directions until tender. Drain well using a colander and set aside.
02 - While the pasta cooks, heat olive oil and butter in a large skillet over medium-high heat. Add the chicken pieces and season with salt, pepper, and dried Italian herbs if using. Sauté until golden brown and cooked through, approximately 6 to 8 minutes. Transfer the chicken to a plate and set aside.
03 - Reduce the heat to medium. In the same skillet, add the chopped onion and cook until softened, about 3 minutes. Add the minced garlic and sauté until fragrant, roughly 30 seconds, stirring constantly to prevent burning.
04 - Pour in the heavy cream and add the cream cheese and grated Parmesan. Stir continuously and simmer gently until the cheeses are fully melted and the sauce is smooth and velvety, about 2 to 3 minutes.
05 - Add the chopped spinach to the skillet and cook, stirring gently, just until wilted, about 1 to 2 minutes.
06 - Return the seared chicken and cooked tortellini to the skillet. Toss everything together gently until evenly coated in the creamy garlic sauce. Taste and adjust seasoning with additional salt and pepper if needed.
07 - Serve immediately in warm bowls, garnished with extra grated Parmesan and chopped fresh parsley if desired.