01 - Bring a large pot of salted water to a boil. Cook the cheese tortellini according to package directions until tender. Drain thoroughly 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 in a single layer and sear for 2–3 minutes per side until a golden crust forms and the meat reaches desired doneness. Transfer to a plate and tent loosely with foil.
03 - Reduce the skillet heat to medium. Add the unsalted butter and allow it to melt and foam. Add the minced shallots and garlic, stirring frequently for about 1 minute until fragrant and softened, taking care not to brown the garlic.
04 - Pour the heavy cream into the skillet, scraping up any browned bits from the bottom. Stir to combine and bring to a gentle simmer. Cook for 2–3 minutes, allowing the sauce to reduce and thicken slightly.
05 - Gradually whisk in the grated Parmesan cheese, stirring continuously until fully melted and the sauce is smooth and velvety.
06 - Return the seared steak and cooked tortellini to the skillet. Toss gently to coat everything evenly in the garlic cream sauce. Cook for 1–2 minutes until heated through.
07 - Transfer to serving plates and sprinkle generously with chopped fresh parsley. Serve immediately while hot.