Mushroom Swiss Grilled Cheese

The skillet was still warm from breakfast when I decided to use up the mushrooms sitting in my fridge. I had Swiss cheese, good rye bread, and twenty minutes before my next meeting. What started as pragmatic leftovers management turned into something I now crave on rainy afternoons. The smell of butter hitting hot cast iron still makes me pause whatever I'm doing.

I made this for my sister when she came over upset about work. She ate half of it standing at the counter, then sat down and finished the rest without saying much. Later she texted asking for the steps, which is her version of a compliment. Sometimes the best recipes are the ones that let people just be quiet and eat.

Ingredients

• Cremini or white button mushrooms (1 cup, 100 g, sliced): Cremini have more flavor, but regular buttons work beautifully too, just make sure they're dry before slicing so they brown instead of steam.
• Shallot (1 small, finely chopped): Shallots bring sweetness without the sharpness of onion, and they cook down almost invisibly into the mushrooms.
• Garlic (1 clove, minced): Add this at the end or it'll burn while the mushrooms are still releasing moisture.
• Swiss cheese (4 slices): Real Swiss melts smoothly and has that subtle nuttiness, avoid pre-shredded if you can because it doesn't melt the same way.
• Unsalted butter (2 tablespoons softened, plus extra for sautéing): Softened butter spreads without tearing the bread, and that extra tablespoon for the mushrooms adds richness you'll taste.
• Rye bread (4 slices): The slight tang of rye complements the mushrooms perfectly, but sourdough or whole wheat work if that's what you have.
• Olive oil (1 tablespoon): Keeps the butter from burning when you're cooking the mushrooms over higher heat.
• Salt and black pepper (to taste): Don't skip seasoning the mushrooms, they need more than you think.
• Fresh thyme leaves (1 teaspoon, optional): If you have it, thyme makes the whole thing smell like a French bistro, but it's still excellent without.

Instructions

Start the mushrooms:

Heat olive oil and 1 tablespoon butter in a skillet over medium heat until the butter foams. Add the 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 let them sit undisturbed for a minute before stirring. Cook for 5 to 7 minutes, stirring occasionally, until they're golden and all the liquid has cooked off, then add the garlic and thyme and cook just one more minute.

Season and set aside:

Taste the mushrooms and add salt and pepper until they taste like something you'd eat with a spoon. Remove the skillet from heat and transfer the mushrooms to a small bowl.

Build the sandwiches:

Lay out your four slices of rye bread and place one slice of Swiss on two of them. Divide the mushroom mixture evenly over the cheese, then top each with another slice of Swiss and close with the remaining bread.

Butter the outsides:

Spread softened butter on the outside of each sandwich, covering all the way to the edges. This is what gives you that golden, crispy crust.

Grill the sandwiches:

Wipe out the skillet and return it to medium low heat. Place both sandwiches in the pan and cook for 3 to 4 minutes per side, pressing gently with a spatula, until the bread is deeply golden and the cheese is fully melted.

Serve:

Let the sandwiches rest for just a minute so you don't burn your mouth, then slice and serve while they're still hot and the cheese is stretchy.

Save

My neighbor smelled this cooking through the open window and knocked on my door to ask what I was making. I ended up making two more sandwiches and we sat on the porch eating them with napkins on our laps. It's rare that something so simple becomes a reason to sit down together, but this one does that.

Flavor Variations

A thin smear of Dijon mustard on the inside of the bread before you build the sandwich adds a sharp little kick that makes everything taste brighter. Gruyère or Emmental work beautifully in place of Swiss if you want something a little more melty or nutty. I've also added a handful of baby spinach on top of the mushrooms when I'm pretending to be healthy, and it works surprisingly well.

What to Serve With It

This sandwich is perfect next to a bowl of tomato soup, which is classic for a reason. A simple green salad with a sharp vinaigrette balances the richness without feeling like too much effort. If you're feeling fancy, a crisp white wine like Sauvignon Blanc or even a light lager makes it feel like a real meal instead of just lunch.

Storage and Reheating

Honestly, this is best eaten right away while the bread is crispy and the cheese is melted. If you have leftovers, wrap them tightly and reheat in a skillet over low heat rather than the microwave, which will make the bread soggy. You can also cook the mushroom mixture ahead and keep it in the fridge for up to three days, then assemble and grill the sandwiches fresh.

• Store cooked mushrooms separately in an airtight container for up to 3 days.
• Reheat assembled sandwiches in a dry skillet over medium low heat, not the microwave.
• Don't freeze these, the texture of the bread and cheese doesn't survive it well.

Save

This sandwich has become my answer to the question of what to make when I want something cozy but don't want to think too hard. It's reliable, it's satisfying, and it makes the whole kitchen smell like you've been cooking all day even though you haven't.

Recipe FAQs

→ Can I use different mushrooms for this sandwich?

Yes, cremini and button mushrooms work wonderfully, but you can also use shiitake, oyster, or portobello mushrooms. Each variety brings its own earthy depth to the sandwich.

→ What cheese alternatives work well in this sandwich?

Gruyère and Emmental are excellent substitutes for Swiss cheese. Both have similar melting qualities and complementary nutty flavors that pair beautifully with mushrooms.

→ How do I prevent the bread from getting soggy?

Ensure the mushrooms are cooked until all excess liquid has evaporated before assembly. Also, serve the sandwich immediately after cooking while the bread is still warm and crispy.

→ Can I make this with white bread instead of rye?

Absolutely. While rye bread adds an earthy, robust flavor that complements the mushrooms, sourdough, ciabatta, or regular white bread all work well. Choose bread that's sturdy enough to hold the filling.

→ What wine pairs best with this sandwich?

Sauvignon Blanc offers bright acidity that cuts through the richness of the cheese and butter. Pinot Grigio or a light Chardonnay also pair nicely with the earthy mushroom flavors.

→ How can I add more flavor to this sandwich?

Layer in Dijon mustard on the bread before assembly, add a sprinkle of fresh thyme while cooking the mushrooms, or include crispy caramelized onions for additional depth and sweetness.