Heat the olive oil in a large saute pan over medium-high heat. Add the beef in an even layer, season generously with salt and pepper and let cook without moving for 3-4 minutes to get a nice sear. Stir and cook on the other side for another 2-3 minutes.Transfer to a plate.
If using ground beef, spread the beef into an even layer then season with salt and pepper. Use a spatula or wooden spoon to break up the beef and cook until no longer pink. Transfer to a plate.
Add the onion and mushrooms, and a little more oil if needed to the now empty pan. Cook on medium heat until softened and caramelized, about 6-8 minutes. Add the garlic and cook for 30 seconds until fragrant.
Sprinkle the gluten-free flour over the onion/mushroom mixture and stir to cook for a minute or so to get rid of the raw flour flavor. Increase the heat and add the wine, stirring until smooth and scraping up the bottom of the pan. Cook for 2-3 minutes until the wine is slightly reduced.
Slowly add the beef broth followed by the Worcestershire sauce, whisking/stirring until smooth and let simmer for 5 minutes or so. Stir in the beef and cashew cream and heat through. Add the parsley and season to taste with salt/pepper.
Serve over gluten-free egg noodles or rice. Enjoy!