Start by cleaning and slicing the mushrooms into even pieces so they cook uniformly. Place the ground beef in a bowl and season it lightly with salt, pepper, garlic powder, and onion powder. Mix gently with your hands or a spoon—just enough to distribute the seasoning without overworking the meat.

Place a large skillet on the stove over medium-high heat and add the olive oil. Allow the oil to heat up for about 30–60 seconds until it shimmers slightly—this ensures a good sear when the beef is added.

Add the seasoned ground beef to the hot skillet. Let it sit undisturbed for about a minute to develop a nice brown crust, then begin breaking it apart using a spatula or wooden spoon. Continue cooking until the beef is fully browned and no longer pink.

Once cooked, carefully remove the beef from the skillet and set it aside on a plate or bowl. Try to leave a little of the rendered fat in the pan—it will add extra flavor to the mushrooms.

In the same skillet, reduce the heat to medium and add the butter. Let it melt completely until it becomes slightly foamy and fragrant.

Add the sliced mushrooms to the skillet in a single layer if possible. Let them cook undisturbed for a minute or two to develop color, then stir occasionally. Continue cooking until they release their moisture and turn golden brown and slightly caramelized.

Return the cooked ground beef back into the skillet with the mushrooms. Stir everything together so the flavors combine evenly, and let it cook for another 2–3 minutes.

Place the Swiss cheese slices directly over the hot beef and mushroom mixture. Cover the skillet with a lid for about 30–60 seconds, just until the cheese melts smoothly over the top.

Once the cheese is melted, turn off the heat. Carefully scoop the mixture into serving bowls, making sure each portion gets a good balance of beef, mushrooms, and melted cheese.

Add any optional toppings like lettuce, avocado, or sauce, and serve immediately while everything is hot, melty, and full of flavor.