Pin It The smell of mushrooms browning in butter always reminds me of rainy Saturday afternoons when the fridge is half-empty and I need something more than plain cheese on toast. I started making this sandwich during one of those weeks when I'd bought mushrooms with grand plans for a stir-fry that never happened. Instead of letting them go soft in the crisper, I sliced them thin, caramelized them with a shallot I found rolling around in the back of the drawer, and tucked them into a grilled cheese. The earthy sweetness against the nutty Swiss and the slight tang of rye bread turned a lazy meal into something I actually looked forward to.
I made this for my neighbor once when she came over to borrow a book and stayed longer than either of us expected. We stood in the kitchen talking while I cooked, and she kept saying it smelled too good to just be grilled cheese. When I sliced it in half and the cheese pulled in long strings, she laughed and said I'd ruined regular grilled cheese for her forever. We ate them standing up at the counter, still warm, with the edges crispy enough to crunch.
Ingredients
- Cremini or white button mushrooms (1 cup, 100 g, sliced): Cremini have a deeper flavor, but regular white buttons work just as well if that's what you have; make sure to slice them thin so they cook evenly and don't release too much water.
- Shallot (1 small, finely chopped): Shallots are milder and slightly sweeter than onions, and they melt into the mushrooms without overpowering the sandwich; if you only have onion, use half and chop it fine.
- Garlic (1 clove, minced): Fresh garlic added at the end keeps its punch without burning, and it makes the whole kitchen smell like something special is happening.
- Swiss cheese (4 slices): Swiss melts beautifully and has a nutty, mild flavor that doesn't fight with the mushrooms; Gruyère or Emmental work too if you want a little more character.
- Unsalted butter (2 tablespoons softened, plus extra for sautéing): Softened butter spreads easily on the bread for even browning, and a little extra in the pan with the mushrooms adds richness without making things greasy.
- Rye bread (4 slices): Rye has a slight sour tang that balances the richness of the cheese and mushrooms; if you're not a fan, sourdough or a hearty whole grain works well too.
- Olive oil (1 tablespoon): A bit of oil mixed with butter for sautéing keeps the butter from burning and gives the mushrooms a silky finish.
- Salt and black pepper (to taste): Don't skip seasoning the mushrooms, they soak up salt and pepper and taste flat without it.
- Fresh thyme (1 teaspoon, optional): Thyme and mushrooms are old friends, and even a small amount makes the filling taste more intentional; dried thyme works in a pinch, just use half.
Instructions
- Sauté the aromatics:
- Heat olive oil and 1 tablespoon butter in a skillet over medium heat until the butter foams, then add the shallot and cook for about a minute until it softens and smells sweet. This step builds the flavor base, so don't rush it.
- Cook the mushrooms:
- Add the sliced mushrooms to the pan and stir them around so they're coated in the fat, then let them cook undisturbed for a few minutes until they start to brown. Keep stirring occasionally for 5 to 7 minutes until they're golden and any liquid they release has cooked off, then stir in the garlic and thyme and cook for another minute.
- Season and set aside:
- Taste the mushrooms and season with salt and black pepper, then remove the pan from the heat and let the mixture cool slightly while you prep the sandwiches. This keeps the bread from getting soggy when you assemble everything.
- Assemble the sandwiches:
- Lay out your rye bread slices and place one slice of Swiss cheese on two of them, then spoon the mushroom mixture evenly over the cheese and top with another slice of cheese before covering with the remaining bread. The double layer of cheese helps hold everything together and ensures every bite is melty.
- Butter the outside:
- Spread softened butter on the outer sides of each sandwich, making sure to get all the way to the edges so the whole surface turns golden and crisp.
- Grill the sandwiches:
- Wipe out the skillet and return it to medium-low heat, then add the sandwiches and cook for 3 to 4 minutes per side, pressing gently with a spatula to help the cheese melt and the bread brown evenly. Low and slow is the key here so the inside gets gooey before the outside burns.
- Slice and serve:
- Let the sandwiches rest for a minute so the cheese sets just a bit, then slice them in half and serve while they're still warm and the cheese is stretchy.
Pin It There's something quietly satisfying about cutting into a grilled cheese and watching the cheese stretch between the halves. The mushrooms peek out from the edges, dark and glossy, and the rye bread smells toasted and slightly sweet. It's the kind of sandwich that makes you slow down and pay attention, even if you're eating it alone at the kitchen table with a book propped open beside you.
How to Pick and Prep Your Mushrooms
Mushrooms hold a lot of water, so wiping them clean with a damp paper towel works better than rinsing them under the tap. If they're really dirty, a quick rinse is fine, just make sure to pat them dry before slicing. Slice them evenly, about a quarter inch thick, so they cook at the same rate and you don't end up with some pieces mushy and others still raw.
Choosing Your Cheese
Swiss cheese melts beautifully and has that nutty, slightly sweet flavor that doesn't overpower the mushrooms. Gruyère is richer and a little sharper, which works if you want more depth, and Emmental is milder with bigger holes and a similar melt. Avoid pre-shredded cheese if you can, it has additives that keep it from melting as smoothly as slices or cheese you shred yourself.
Serving and Pairing Ideas
This sandwich is rich enough to stand on its own, but it's even better with a bowl of tomato soup for dipping or a simple green salad dressed with lemon and olive oil to cut through the richness. If you're feeling fancy, a glass of crisp white wine like Sauvignon Blanc or a light beer pairs nicely.
- Add a thin layer of Dijon mustard to the inside of the bread before assembling for a subtle tangy kick.
- Serve with pickles or cornichons on the side for a bright, acidic contrast.
- Leftovers reheat well in a skillet over low heat, just cover the pan with a lid to help the cheese melt again.
Pin It Once you've made this sandwich, plain grilled cheese will feel like it's missing something. Keep it in your back pocket for those days when you want comfort with just a little more intention.
Recipe Questions & Answers
- → Can I use different mushrooms for this sandwich?
Yes, cremini and white button mushrooms work wonderfully, but you can also use portobello, shiitake, or oyster mushrooms. Just slice them uniformly so they cook evenly. Firmer varieties like portobellos may take slightly longer to sauté.
- → What's the best way to prevent soggy bread?
Make sure to cook the mushrooms until all liquid has evaporated before assembling the sandwich. Also, allow the mushroom filling to cool slightly before spreading it on the cheese to avoid steam making the bread wet during cooking.
- → Can I make this ahead of time?
You can prepare the sautéed mushrooms up to 2 hours in advance and store them in an airtight container at room temperature. Assemble and cook the sandwiches fresh for the best texture and melted cheese.
- → What bread alternatives work well?
While rye bread provides a distinctive flavor, you can substitute sourdough, whole wheat, or even brioche. Each will create a different texture—sourdough offers tanginess, while brioche provides richness.
- → How do I get the cheese perfectly melted?
Cook the sandwich on medium-low heat and press gently with a spatula as it cooks. Covering the skillet with a lid for the last minute of cooking traps steam and helps the cheese melt faster without over-browning the bread.
- → What drinks pair well with this sandwich?
Tomato soup is the classic pairing for grilled cheese. For wine, try Sauvignon Blanc or a light Pinot Grigio. Sparkling cider or a crisp lager also complement the earthy mushrooms and rich cheese beautifully.