Heat olive oil in a large skillet or pot over medium-high heat.
Add the cubed sirloin steak to the skillet and season with salt, black pepper, and dried Italian seasoning.
Cook the steak for 4 to 5 minutes, stirring occasionally, until browned on all sides but not fully cooked through. Remove the steak from the skillet and set aside.
In the same skillet, add the minced garlic and sauté for about 30 seconds until fragrant.
Pour in the beef broth and heavy cream, stirring to combine and scraping up any browned bits from the bottom of the skillet.
Add the refrigerated cheese tortellini to the skillet and bring the mixture to a simmer.
Cook the tortellini for 5 to 7 minutes, stirring occasionally, until tender and most of the liquid has reduced.
Return the browned steak cubes to the skillet and stir in the grated Parmesan cheese.
Add the fresh baby spinach and cook for an additional 1 to 2 minutes until the spinach wilts and the steak is cooked through.
Remove from heat and sprinkle with chopped fresh parsley before serving.