Save The smell of mushrooms browning in butter used to drift up from my neighbor's kitchen every Saturday morning, and I'd wonder what she was making that smelled so impossibly good. One afternoon she invited me in and handed me a grilled cheese that was nothing like the ones I grew up with. The rye bread was crisp and dark, the cheese gooey, and there were tender, earthy mushrooms tucked inside. I went home that day determined to recreate it, and after a few tries, I got it just right.
I made this for my sister on a rainy Tuesday when she showed up at my door soaked and exhausted from work. She sat at my kitchen table wrapped in a blanket while I cooked, and when I set the sandwich in front of her, she took one bite and closed her eyes. She didn't say anything for a minute, just chewed slowly, and then she looked at me and said it tasted like being taken care of. That's when I knew this recipe was a keeper.
Ingredients
- Cremini or white button mushrooms: I always go for cremini because they have a deeper, almost nutty flavor, but white buttons work beautifully too and they're usually cheaper.
- Shallot: Shallots are sweeter and more delicate than onions, and they melt into the mushrooms without overpowering them.
- Garlic: Just one clove is enough to add warmth without making the sandwich taste too sharp or raw.
- Swiss cheese: It melts like a dream and has that mild, slightly sweet flavor that doesn't compete with the mushrooms.
- Unsalted butter: I use unsalted so I can control the seasoning, and softened butter spreads easier on the bread without tearing it.
- Rye bread: The slight sourness and dense texture hold up to all the moisture from the mushrooms and cheese.
- Olive oil: I use this to start the mushrooms because it keeps the butter from burning at higher heat.
- Fresh thyme: Optional, but it adds a subtle woodsy note that makes the whole sandwich smell like something from a bistro.
Instructions
- Start the aromatics:
- Heat the olive oil and a tablespoon of butter in your skillet over medium heat, then add the shallot. Let it cook for about a minute until it softens and starts to smell sweet.
- Cook the mushrooms:
- Toss in the sliced mushrooms and let them cook undisturbed for a minute before stirring. Keep cooking for 5 to 7 minutes until they turn golden and all the liquid they release has evaporated, then stir in the garlic and thyme and cook for one more minute.
- Season and set aside:
- Taste the mushrooms and add salt and black pepper as needed. Remove the skillet from the heat and transfer the mushrooms to a plate.
- Assemble the sandwiches:
- Lay out your rye bread slices and place a slice of Swiss on two of them, then spoon the mushroom mixture evenly over the cheese and top with another slice of Swiss. Cover each with the remaining bread slices.
- Butter the outsides:
- Spread softened butter generously on the outside of each sandwich so they'll get golden and crispy. Don't skip this step or the bread will just steam instead of crisp up.
- Grill the sandwiches:
- Wipe out the skillet and return it to medium low heat, then add the sandwiches. Cook for 3 to 4 minutes on each side, pressing gently with a spatula, until the bread is deeply golden and the cheese is fully melted.
- Slice and serve:
- Let the sandwiches rest for a minute before slicing them in half. Serve warm while the cheese is still gooey.
Save The first time I made this for a friend who claimed she didn't like mushrooms, I held my breath as she took a bite. She paused, looked at the sandwich, then at me, and said she might have been wrong about mushrooms her whole life. We ended up making another round that night, and she took notes on her phone while I cooked. It's one of my favorite compliments I've ever received in the kitchen.
Choosing Your Bread
Rye bread is my go to here because it has enough structure to hold everything together and a slight tang that cuts through the richness of the cheese. I've also used sourdough when I didn't have rye on hand, and it worked beautifully. Whatever bread you choose, make sure it's sturdy and not too soft, or it'll get soggy from the mushrooms.
Swapping the Cheese
Swiss is classic, but I've made this with Gruyere when I wanted something a little funkier and more complex. Emmental is another great option if you like a milder, nuttier flavor. If you're feeling adventurous, a mix of cheeses works too, just make sure at least one of them melts well or you'll end up with a greasy, separated mess.
Serving and Pairing Ideas
This sandwich is hearty enough to stand on its own, but it's even better with a bowl of tomato soup for dipping. I've also served it alongside a simple green salad with a lemon vinaigrette to cut the richness. On nights when I want to feel fancy, I pour a glass of chilled Sauvignon Blanc, and it feels like I'm eating at a little cafe somewhere in Europe.
- Add a thin smear of Dijon mustard to the inside of the bread before assembling for a subtle kick.
- Serve with pickles or cornichons on the side for a tangy contrast.
- Leftovers reheat well in a dry skillet over low heat, just cover with a lid to help the cheese melt again.
Save This sandwich has become my answer to gray days, unexpected guests, and moments when I need something comforting but a little special. I hope it finds a place in your kitchen the way it has in mine.
Recipe Q&A
- → Can I use a different type of mushroom?
Absolutely. While cremini mushrooms work beautifully, you can substitute with white button mushrooms, oyster mushrooms, or a mix for varied textures and flavors. Ensure they're sliced evenly for consistent cooking.
- → What cheese alternatives work well?
Gruyère and Emmental are excellent substitutes for Swiss cheese, offering rich, nutty flavors. Fontina or Jarlsberg also melt beautifully and complement the earthy mushrooms nicely.
- → Can I make this ahead of time?
Prepare the mushroom filling up to 4 hours in advance and refrigerate. Assemble and cook the sandwiches fresh to ensure the bread stays crispy and cheese melts evenly.
- → How do I prevent soggy bread?
Make sure mushrooms are cooked until all liquid evaporates. Butter the bread generously and cook on medium-low heat to allow the exterior to crisp before the cheese fully melts.
- → What are good side pairings?
Tomato soup is the classic pairing. For wine, try a crisp Sauvignon Blanc. A simple green salad or roasted vegetable medley also complements the rich, umami flavors beautifully.
- → Can I add other ingredients?
Dijon mustard adds tangy depth, while caramelized onions bring sweetness. Fresh thyme is already optional in the filling. Avoid watery vegetables that might make the bread soggy.