Bring a large pot of salted water to a boil and drop in the ravioli. Cook according to the package directions, usually around 3 to 4 minutes for fresh or refrigerated ravioli. Drain gently and set aside, tossing lightly with a touch of olive oil so the pieces don't stick together.
Pat the steak cubes dry and season generously with salt and pepper. Heat the olive oil and half the butter in a large skillet over medium-high heat until shimmering. Add the steak in a single layer and sear for 2 to 3 minutes per side until a deep brown crust forms, then remove it to a plate.
Lower the heat to medium and add the remaining butter to the same skillet, letting all those browned steak bits flavor it. Stir in the minced garlic and cook for about 60 seconds until fragrant, watching closely so it doesn't burn and turn bitter.
Pour in the beef broth and scrape up any browned bits stuck to the bottom of the pan. Add the heavy cream, Italian seasoning, and red pepper flakes, then let the mixture come to a gentle simmer for 2 to 3 minutes until it starts to thicken.
Sprinkle in the freshly grated Parmesan a little at a time, stirring constantly so it melts smoothly instead of clumping. The sauce should turn glossy and coat the back of a spoon once all the cheese is incorporated.
Return the seared steak and any accumulated juices to the skillet, followed by the drained ravioli. Gently fold everything together with a silicone spatula so the ravioli stays intact while getting fully coated in sauce.
Let everything simmer together for 1 to 2 minutes just to heat through, then remove the skillet from the heat. Sprinkle the fresh parsley over the top and serve immediately while the sauce is still warm and glossy.