01 - Bring a large pot of salted water to a rolling boil. Add the cheese tortellini and cook according to package directions until they float and are tender. Drain through a colander and set aside.
02 - While the pasta cooks, heat olive oil and butter in a large skillet over medium-high heat. Season the chicken pieces with salt, pepper, and dried Italian herbs if using. Add the chicken to the skillet in a single layer and cook 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 and translucent, about 3 minutes. Add the minced garlic and sauté until fragrant, approximately 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 all the cheese has melted and the sauce is smooth and velvety, about 2 to 3 minutes.
05 - Add the chopped spinach to the sauce and stir gently. Cook just until the spinach has wilted and is evenly incorporated, approximately 1 to 2 minutes.
06 - Return the seared chicken and cooked tortellini to the skillet. Toss everything together gently until the pasta and chicken are thoroughly coated in the creamy garlic sauce. Taste and adjust seasoning with additional salt and pepper if needed.
07 - Transfer to warm serving plates or bowls immediately. Garnish with extra grated Parmesan and freshly chopped parsley if desired. Pair with a crisp white wine such as Sauvignon Blanc or Pinot Grigio for a complete dining experience.