Save The smell of mushrooms browning in butter used to wake up my college roommate every Saturday morning. I'd started making these sandwiches during finals week when I needed something more comforting than a plain grilled cheese but couldn't handle anything complicated. The earthy smell of thyme mixing with garlic became my signal that everything would be okay, even if I had three exams ahead. That little skillet and a loaf of rye bread got me through an entire semester.
I made this for my brother once when he came over unannounced and starving after a long drive. He sat at the counter watching me cook the mushrooms down, skeptical that a sandwich could be worth the wait. When he took the first bite, he stopped talking completely for a solid minute. He still texts me sometimes just asking if I remember that sandwich, which is the highest compliment he's ever given my cooking.
Ingredients
- Cremini or white button mushrooms: Cremini have a deeper flavor, but regular white buttons work beautifully too, just make sure they're sliced thin so they cook evenly and don't release too much water.
- Shallot: This adds a delicate sweetness that onions can't quite match, and one small shallot is enough to perfume the whole pan without overpowering the mushrooms.
- Garlic: Add it near the end so it gets fragrant but doesn't burn, which would make everything taste bitter instead of savory.
- Swiss cheese: It melts like a dream and has that nutty, slightly sweet flavor that loves mushrooms, plus it doesn't get greasy like some sharper cheeses.
- Unsalted butter: You'll use some for the mushrooms and some for the bread, and using unsalted lets you control exactly how much salt goes into every layer.
- Rye bread: The caraway seeds in rye add an unexpected brightness that cuts through the richness, and it gets wonderfully crisp in the pan.
- Olive oil: Just a tablespoon keeps the butter from burning while the mushrooms cook down and concentrate their flavor.
- Fresh thyme: Optional, but those tiny leaves add a woodsy note that makes the whole sandwich smell like something from a French bistro.
Instructions
- Start the aromatics:
- Heat olive oil and a tablespoon of butter in your skillet over medium heat until the butter foams. Add the chopped shallot and let it soften for about a minute, stirring so it doesn't brown too fast.
- Cook the mushrooms:
- Toss in the sliced mushrooms and stir them around to coat with the fat. Let them cook without stirring too much for 5 to 7 minutes so they release their moisture and turn golden at the edges, then add the garlic and thyme and cook one more minute until everything smells amazing.
- Season and set aside:
- Sprinkle with salt and black pepper, taste a piece, then take the skillet off the heat. Transfer the mushroom mixture to a small bowl so you can use the same pan for grilling.
- Assemble the sandwiches:
- Lay out your four slices of rye bread and put one slice of Swiss on two of them, spoon the warm mushroom mixture over the cheese, then top with another slice of Swiss and close with the remaining bread. Butter the outside of each sandwich generously.
- Grill to golden perfection:
- Wipe the skillet clean, set it over medium low heat, and place both sandwiches in the pan. Cook for 3 to 4 minutes on each side, pressing gently with your spatula, until the bread is deeply golden and the cheese has melted into the mushrooms.
- Slice and serve:
- Cut each sandwich in half while it's still hot so the cheese stretches beautifully. Serve immediately while everything is crispy and melty.
Save There's a moment right after you flip the sandwich when you can smell the rye toasting and see the cheese just starting to ooze out the sides. That's when I always pause and think about how something this simple can feel so luxurious. It's become my go to meal when I need to remind myself that cooking doesn't have to be complicated to be special.
Choosing Your Bread
Rye is my favorite here because of that slight tang and the way it crisps up, but I've made this with sourdough when that's all I had and it was equally delicious. The key is using something sturdy enough to hold the mushrooms without getting soggy, so avoid soft sandwich bread that'll fall apart. If you can find a marbled rye or a seeded multigrain, those add even more texture and flavor.
Cheese Swaps That Work
Swiss is classic, but Gruyère takes this sandwich into fancy territory with its deeper, almost caramelized flavor. Emmental is milder and melts beautifully if you want something less assertive, and I've even used fontina when I wanted something creamier. Just avoid pre shredded cheese because it has coatings that prevent smooth melting and you'll end up with a grainy texture instead of that perfect stretch.
What to Serve Alongside
This sandwich begs for something acidic to cut through all that richness. A simple arugula salad with lemon vinaigrette is perfect, or go classic with tomato soup for dipping. I sometimes just slice a dill pickle on the side and call it a meal.
- A crisp white wine like Sauvignon Blanc echoes the acidity you need and feels celebratory.
- Hot apple cider works beautifully in fall when you want something cozy and non alcoholic.
- Even a cold beer, something light like a pilsner, balances the richness without overwhelming the mushroom flavor.
Save This sandwich proves that comfort food doesn't have to be boring or apologetic. Make it once and it'll become part of your rotation, the thing you crave on rainy afternoons and the recipe you text to friends who ask what's for lunch.
Recipe Q&A Section
- → Can I use different types of mushrooms?
Yes, cremini and button mushrooms work well, but you can also use portobello, oyster, or shiitake mushrooms. Each variety brings different earthy notes to the sandwich. Ensure mushrooms are cleaned and sliced evenly for consistent cooking.
- → What cheese alternatives work best?
Gruyère, Emmental, and Fontina are excellent substitutes for Swiss cheese. For a sharper flavor, try aged cheddar or Gouda. Each cheese will give the sandwich a unique character while maintaining that creamy, melted quality.
- → Can I make this vegan?
Absolutely. Use plant-based butter and dairy-free Swiss cheese alternatives. The sautéed mushrooms are naturally flavorful and hearty enough to carry the sandwich. Ensure your bread is vegan-friendly as some rye breads contain dairy.
- → How do I prevent soggy bread?
Make sure mushrooms release all their moisture during cooking—cook them until any liquid has fully evaporated. Don't assemble the sandwich too far in advance. Use quality bread with a sturdy crumb structure and butter the exterior generously for a protective crispy crust.
- → What sides pair well with this sandwich?
Tomato soup is a classic pairing that complements the earthy mushrooms beautifully. Alternatively, serve with a crisp white wine like Sauvignon Blanc, a simple green salad, or roasted vegetables for a complete meal.
- → Can I prepare mushrooms ahead of time?
Yes, sauté the mushroom mixture up to 2 hours ahead and refrigerate in a covered container. Warm gently before assembling if desired. This makes assembly quicker and easier on busy days without sacrificing flavor.