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. Add the diced chicken, season generously with salt, pepper, and Italian herbs if using. Sauté until golden brown and cooked through, approximately 6 to 8 minutes. Transfer the chicken to a plate and keep warm.
03 - Reduce the skillet heat to medium. Add the chopped onion and cook until softened and translucent, about 3 minutes. Stir in the minced garlic and sauté until fragrant, roughly 30 seconds, taking care not to brown it.
04 - Pour the heavy cream into the skillet and add the cream cheese and grated Parmesan. Stir continuously over gentle heat until the cheeses have fully melted and the sauce is silky smooth, about 2 to 3 minutes.
05 - Add the chopped spinach to the cream sauce and stir gently until just wilted, about 1 to 2 minutes. Avoid overcooking to preserve its vibrant color and texture.
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 as needed. Serve immediately, garnished with extra Parmesan and fresh parsley if desired.