Ingredients
Equipment
Method
- Prepare the Caramelized Onions: Heat 2 tablespoons of olive or avocado oil in a large skillet over medium heat. Once the oil is shimmering, add the thickly sliced yellow onions and sprinkle lightly with salt. Stir the onions to coat them evenly in the oil, then allow them to cook for 5–7 minutes, stirring occasionally until they begin to turn golden. Reduce the heat to low and continue cooking for 20–25 minutes, stirring every few minutes to prevent sticking or burning. The onions should become deeply browned, soft, and richly sweet. Once caramelized, transfer them to a separate plate and set aside for assembly.
- Shape and Season the Beef Patties: While the onions are cooking, divide the 2 pounds of ground beef into four equal portions. Gently shape each portion into a patty about ¾-inch thick, being careful not to overwork the meat to keep it tender. Press your thumb lightly into the center of each patty to prevent puffing during cooking. Season both sides generously with coarse salt and freshly cracked pepper.
- Cook the Burgers: In a large cast iron skillet, carbon steel pan, or griddle, heat the remaining 2 tablespoons of oil over medium heat until shimmering. Add the beef patties and cook for 5–7 minutes on the first side, depending on desired doneness. Flip the patties carefully and cook another 5–7 minutes for a medium burger. Place a slice of Swiss cheese on top of each patty during the last 2–3 minutes of cooking to melt. Once done, remove the patties from the skillet and set them aside, loosely covering with foil to keep warm.
- Sauté the Mushrooms: In the same skillet used for the burgers (with the rendered beef fat still in the pan), add the thinly sliced mushrooms.Sprinkle lightly with salt and increase the heat to medium-high. Sauté the mushrooms for 5–7 minutes, stirring occasionally, until they are golden brown and fragrant. Add the minced garlic and cook for another 1–2 minutes until aromatic.
- Create the Mushroom Sauce: Pour 2 cups of beef stock into the pan with the mushrooms, stirring to deglaze the pan and incorporate all the flavorful browned bits.Continue cooking on high heat until the liquid reduces by half and thickens into a rich, glossy sauce. Taste and adjust seasoning with salt and freshly cracked pepper.If desired, stir in 1 teaspoon of unsalted butter and some minced fresh parsley for extra flavor and a silky texture.
- Toast the Buns: While the mushroom sauce is reducing, toast the hamburger buns. If possible, brush the cut sides with a little garlic butter or olive oil, then toast them on a skillet over medium heat until golden brown. This step ensures the buns stay firm and won’t become soggy once the juicy patties and toppings are added.
- Assemble the Burgers: Place the toasted bottom bun on a plate. Add the cooked beef patty with melted Swiss cheese, followed by a generous layer of caramelized onions. Spoon over the savory mushroom sauce, ensuring it drapes nicely over the burger.Top with the other half of the toasted bun to complete the assembly. Serve immediately while hot, with extra mushroom sauce on the side for dipping if desired.
- Optional Rest and Serving Tips: Although tempting to eat immediately, allow the burgers to rest for 3–5 minutes after cooking. This helps the juices redistribute throughout the meat, keeping each bite tender and flavorful. Serve with a side of your favorite vegetables, salad, or fries for a complete meal.
Notes
- Take your time with caramelizing onions; low and slow cooking develops a rich, sweet flavor.
- Avoid overworking the ground beef when shaping patties to keep them tender and juicy.
- Use a meat thermometer to ensure your burgers reach the desired internal temperature without overcooking.
- Sauté mushrooms in the rendered beef fat for maximum flavor and depth.
- Toast buns separately or brush with garlic butter to prevent sogginess and add extra flavor.
- Make components ahead of time—caramelized onions, mushroom sauce, and shaped patties can be refrigerated for easy cooking later.