01 - Bring a large pot of salted water to a boil. Cook the cheese tortellini according to package instructions until al dente. Drain through a strainer and set aside.
02 - Pat the sirloin pieces dry and season generously with salt and freshly ground black pepper. Heat olive oil in a large skillet over medium-high heat until shimmering. Add the steak pieces in a single layer and sear for 2–3 minutes per side until a deep golden-brown crust forms and the meat reaches desired doneness. Transfer the steak to a plate and tent loosely with foil.
03 - Reduce the skillet heat to medium. Add the unsalted butter and let it melt, scraping up any browned bits from the bottom. Sauté the minced shallots and garlic for about 1 minute until fragrant and softened, taking care not to let the garlic brown.
04 - Pour in the heavy cream, stirring to incorporate all the fond from the pan. Bring the sauce to a gentle simmer and cook for 2–3 minutes, allowing it to reduce and thicken slightly.
05 - Gradually stir in the grated Parmesan cheese, continuing to stir until fully melted and the sauce is smooth and velvety.
06 - Return the cooked tortellini and seared steak pieces to the skillet. Toss gently to coat everything evenly in the garlic cream sauce and heat through for 1–2 minutes.
07 - Sprinkle generously with chopped fresh parsley. Serve immediately while hot, paired with a crisp green salad and a glass of Chianti if desired.