Add the ground beef, almond flour, egg, salt, pepper, garlic powder, onion powder, and Worcestershire sauce (if you're using it) to a large bowl. Use your hands or a fork to mix everything gently. Try not to overwork the beef—stop as soon as everything looks evenly combined and the mixture sticks together.

Divide the mixture into four equal portions. Shape each portion into a thin patty, about the size of your palm, keeping the thickness roughly even so they cook uniformly. Press a small indent into the center of each patty—this helps them stay flat instead of puffing up as they cook.

Place a heavy skillet on the stove and turn the heat to medium-high. Once hot, add 1 tablespoon of butter and let it melt. Place the patties into the skillet without overcrowding. Sear each side for about 2–3 minutes, or until the outside has a deep brown crust. Once cooked, transfer the patties to a plate and lightly cover with foil to keep them warm.

Without washing the skillet, add 2 tablespoons of butter. Once melted, add the chopped onion and cook for about 2–3 minutes, stirring occasionally, until the onion looks soft and translucent. Add the sliced mushrooms and continue cooking until the mushrooms soften and turn golden brown, releasing some of their moisture.

Pour in the beef broth and stir well, scraping the bottom of the pan to lift any browned bits from cooking the patties. Let the mixture simmer gently for about 3–5 minutes so the broth reduces slightly and the flavors deepen. Stir in the Dijon mustard and taste the broth; if needed, adjust seasoning.

Turn the heat down to medium-low and slowly whisk in the heavy cream. Once the cream is mixed in, sprinkle the xanthan gum across the surface in tiny pinches while whisking continuously. Keep whisking until the gravy thickens to a smooth consistency. Taste and adjust with salt and pepper as needed.

Place the cooked patties back into the skillet, spooning some gravy over the tops. Let them simmer together for another 2–3 minutes so the flavors meld and the meat absorbs some of the sauce. Finish with a sprinkle of chopped parsley, and serve warm with your favorite keto sides.