Season the chicken: Sprinkle both sides with salt, pepper, and half the Italian seasoning. Keep the pieces thin so they cook quickly and stay tender.
Sear the chicken: Heat olive oil in a large skillet over medium-high.
Add chicken in a single layer and cook 3–4 minutes per side until golden and cooked through. Transfer to a plate and tent with foil.
Start the sauce base: Reduce heat to medium. Add butter to the same skillet.
Stir in garlic and the remaining Italian seasoning plus red pepper flakes. Cook 30–60 seconds until fragrant, scraping up any browned bits.
Make it saucy: Pour in chicken broth and tomato sauce. Stir and bring to a gentle simmer for 2–3 minutes to blend flavors.
Add cream and cheese: Lower heat to medium-low.
Stir in heavy cream and Parmesan until smooth. Taste and adjust salt and pepper. You want a balanced, savory sauce with a hint of tang from the tomato.
Cook the ravioli: While the sauce simmers, boil a large pot of salted water.
Add ravioli and cook according to package directions until just tender. Reserve 1/2 cup pasta water, then drain.
Finish in the skillet: Add cooked ravioli to the sauce, tossing gently. If it seems thick, splash in reserved pasta water until glossy and well-coated.
Return the chicken: Slice chicken into strips and fold into the ravioli.
Add spinach, if using, and let it wilt for 30–60 seconds.
Serve: Top with extra Parmesan and chopped basil or parsley. Serve hot with a green salad or garlic bread.