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Swiss Mushroom Melt Sandwich Recipe

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★★★★★

4.7 from 150 reviews

The Swiss Mushroom Melt Sandwich is a savory, comforting vegetarian delight featuring deeply caramelized onions, sautéed cremini mushrooms with garlic and thyme, melted Swiss cheese, and a hint of Dijon mustard, all layered between buttery toasted sourdough bread. Perfect for a hearty lunch or a satisfying dinner, this recipe combines rich flavors and textures with simple technique.

Ingredients

Scale

Caramelized Onions

  • 2 large yellow onions, thinly sliced
  • 2 tablespoons olive oil
  • 1 tablespoon butter
  • 1 teaspoon brown sugar
  • 1/2 teaspoon balsamic vinegar
  • Salt and freshly ground black pepper to taste

Sautéed Mushrooms

  • 1 pound cremini mushrooms, sliced
  • 2 tablespoons olive oil
  • 2 cloves garlic, minced
  • 1/4 cup dry white wine (optional, but recommended)
  • 1 tablespoon fresh thyme leaves
  • Salt and freshly ground black pepper to taste

Sandwich Assembly

  • 4 slices sourdough bread (or your favorite bread)
  • 4 ounces Swiss cheese, thinly sliced
  • 2 tablespoons butter, softened
  • 1 tablespoon Dijon mustard (optional)

Instructions

  1. Slice Onions: Peel and thinly slice the yellow onions to prepare for caramelization.
  2. Cook Onions: In a large skillet, heat olive oil and butter over medium-low heat. Add the sliced onions, stirring to coat them well.
  3. Caramelize Onions: Cook the onions on very low heat for 30-45 minutes, stirring occasionally, until they become deep golden brown and very soft. Reduce heat if the onions start to brown too quickly to avoid burning.
  4. Add Sugar and Vinegar: Stir in the brown sugar and balsamic vinegar, cooking for another 2-3 minutes while stirring constantly until the sugar dissolves and the balsamic vinegar is absorbed.
  5. Season Onions: Season the caramelized onions with salt and freshly ground black pepper to taste. Remove from the skillet and set aside.
  6. Prepare Mushrooms: Clean and slice the cremini mushrooms for sautéing.
  7. Cook Mushrooms: In the same skillet, heat olive oil over medium-high heat. Add the mushrooms and cook for 8-10 minutes, stirring occasionally, until browned and softened. Cook in batches if needed to avoid overcrowding the pan.
  8. Add Garlic and Thyme: Add minced garlic and fresh thyme leaves to the mushrooms. Cook for an additional minute, stirring constantly, until the garlic becomes fragrant.
  9. Deglaze with Wine: Pour dry white wine into the skillet and scrape up any browned bits from the pan’s bottom. Let the wine reduce for 1-2 minutes until mostly evaporated.
  10. Season Mushrooms: Season the sautéed mushrooms with salt and freshly ground black pepper to taste. Remove from the skillet and set aside.
  11. Prepare Bread: Lightly butter one side of each slice of sourdough bread.
  12. Apply Mustard: Spread a thin layer of Dijon mustard on the unbuttered side of two slices of bread for extra flavor.
  13. Assemble Sandwiches: Place the bread slices buttered side down in a clean skillet over medium-low heat. Lay half of the Swiss cheese on each slice.
  14. Add Fillings: On one slice, pile half of the caramelized onions and half of the sautéed mushrooms on top of the cheese. Repeat on the other slice.
  15. Cook and Melt Cheese: Cook the sandwiches for 3-5 minutes per side, until the bread is golden brown and toasted and the cheese is melted and gooey. Cover the skillet with a lid to help the cheese melt faster.
  16. Serve: Carefully remove the sandwiches from the skillet. Stack one slice on top of the other to form a full sandwich. Cut in half and serve immediately while warm.

Notes

  • Cooking onions low and slow is key to achieve deep caramelization and maximum sweetness.
  • Cooking mushrooms in batches prevents overcrowding, allowing them to brown properly instead of steaming.
  • Using a lid while melting cheese helps speed up the process and ensures gooey cheese.
  • Dijon mustard is optional but adds a nice tangy contrast to the rich flavors.
  • You can substitute sourdough with any crusty bread like ciabatta or multigrain for different flavor variations.
  • If you prefer, the white wine can be omitted or replaced with vegetable broth for a non-alcoholic version.

Keywords: Swiss mushroom melt, caramelized onion sandwich, sautéed mushrooms, vegetarian sandwich, cheesy mushroom sandwich, stovetop sandwich, sourdough sandwich

Find it online: https://victoriablair.com/swiss-mushroom-melt-sandwich-recipe/