Ingredients:

  • 2 Tbsp Unsalted Butter
  • 1 lb Mixed Mushrooms (Cremini/Portobello), sliced thinly
  • 2 cloves Garlic, minced finely
  • 1 tsp Fresh Thyme Leaves, chopped
  • 2 Tbsp Dry Red Wine or Sherry (optional, for deglazing)
  • Salt & Black Pepper, to taste
  • 5 lb Ground Beef (80/20 Chuck)
  • 1 tsp Worcestershire Sauce
  • 1/2 tsp Onion Powder
  • 4 slices Swiss Cheese (Emmentaler or Gruyère)
  • 1 Tbsp Neutral Oil (Canola or Vegetable)
  • 4 Brioche Buns or Seeded Baps, split and toasted
  • Mayonnaise (Optional)
  • Dijon Mustard (Optional)

Instructions:

  1. Form the Patties: Gently combine the ground beef, Worcestershire sauce, onion powder, salt, and pepper in a bowl. Do not overmix. Divide the meat into four equal portions and lightly form into patties, slightly wider than the buns.
  2. Create a Dimple: Press a shallow indentation into the centre of each patty. This prevents the burger from ballooning while cooking.
  3. Toast the Buns: Spread a thin layer of butter (or simply dry toast) the cut side of the buns. Toast in a separate skillet or under the grill until lightly golden brown. Set aside.
  4. Sauté the Mushrooms (The Hard Part): Melt the butter in the skillet over medium-high heat. Add the sliced mushrooms. Let them sit for 2-3 minutes to begin browning without stirring. Continue to cook, stirring occasionally, until all moisture has evaporated and the mushrooms are deeply golden brown and reduced in volume (about 6-8 minutes).
  5. Flavour Building & Deglaze: Reduce heat to medium. Add the minced garlic and thyme and cook for 1 minute until fragrant. Pour the red wine or sherry into the pan and scrape up any browned bits (the fond). Cook until the liquid has almost completely evaporated and the mushrooms are glossy and concentrated. Season with salt and pepper. Transfer the ragout to a bowl and keep warm. Wipe out the skillet.
  6. Sear the Patties: Add the neutral oil to the cleaned skillet and heat over high heat until shimmering. Place the patties in the hot pan. Cook undisturbed for 3 to 4 minutes for a good sear. Flip the patties.
  7. Cheese Melt & Rest: Cook the second side for 2-3 minutes. When the burgers are nearly done (internal temperature around 155°F / 68°C), top each patty generously with a slice of Swiss cheese. Cover the skillet briefly (30 seconds to 1 minute) to allow the cheese to fully melt. Remove the burgers and let them rest on a plate for 2-3 minutes.
  8. Assemble: Spread the toasted bun bases with mayonnaise or Dijon mustard (if using). Place the rested burger patty on the base. Spoon a generous helping of the warm Mushroom Ragout directly over the melted cheese. Place the bun top on, secure, and serve immediately.