Description
This Mushroom Patty Melt recipe features caramelized onions, marinated roasted portobello mushrooms, Swiss cheese, and rye bread toasted to golden perfection. Combining savory flavors with melty cheese and a hint of balsamic tang, it’s a hearty and satisfying vegetarian sandwich perfect for a comforting meal.
Ingredients
For the Onions and Mushrooms
- ½ cup vegetable oil (divided)
- 1 colossal onion (thinly sliced, 565g, about 3 cups)
- 4 large portobello mushrooms
- 2 garlic cloves (minced, 1 Tbsp)
- ¼ cup balsamic vinegar
- ⅛ cup soy sauce
- ½ tsp dried thyme
For the Sandwich Assembly
- 8 slices rye bread
- ⅓ cup mayonnaise
- 8 slices Swiss cheese
- ¼ tsp salt
- 4 Tbsp butter (divided)
Instructions
- Preheat Oven and Prepare Ingredients: Preheat your oven to 400°F (200°C) and gather all your ingredients to have them ready for cooking.
- Caramelize the Onions: Heat ¼ cup of vegetable oil in a medium skillet over medium heat. Add the thinly sliced onions and cook, stirring occasionally, for about 45 minutes until they become golden and caramelized. Remove from the pan and set aside, then wipe out the pan.
- Clean the Mushrooms: While the onions cook, remove stems and gills from the portobello mushrooms. Place the mushroom caps with the cap side down on a parchment-lined baking sheet.
- Marinate the Mushrooms: In a small bowl, whisk together minced garlic, balsamic vinegar, remaining ¼ cup vegetable oil, soy sauce, and dried thyme. Pour this marinade evenly over the mushroom caps on the baking sheet, allowing some overflow. Roast the mushrooms in the preheated oven for 20 minutes.
- Slice the Mushrooms: Once roasted and cooled slightly, slice the mushrooms for sandwich assembly.
- Assemble the Patty Melts: Lay out the rye bread slices and spread mayonnaise evenly over all 8 slices. Add a slice of Swiss cheese and a generous portion of caramelized onions on each slice. On 4 of the bread slices, add the sliced roasted mushrooms and sprinkle with salt. Close each with another slice to form sandwiches.
- Cook the Sandwiches: Melt 1 Tbsp of butter in the skillet over medium heat. Place two sandwiches in the skillet and toast for 3 to 4 minutes until golden brown. Add another tablespoon of butter, carefully flip the sandwiches, and cook for another 3 to 4 minutes. Repeat this process with the remaining two sandwiches and butter.
- Serve: Remove sandwiches from the skillet and serve hot. Enjoy the melty, savory Mushroom Patty Melts fresh off the pan!
Notes
- Use parchment paper when roasting mushrooms to prevent sticking and make cleanup easier.
- Adjust the caramelization time of onions based on your stove’s heat and pan type.
- For a vegan option, substitute mayonnaise with vegan mayo and Swiss cheese with a plant-based cheese alternative.
- Make sure to not overcrowd the skillet when toasting sandwiches for even browning.
- Leftover sandwiches can be reheated in a skillet or oven for best texture.
- Prep Time: 20 minutes
- Cook Time: 55 minutes
- Category: Sandwich
- Method: Baking
- Cuisine: American
