Save One rainy Tuesday, I opened my fridge to find a bag of wilting spinach and half a block of cheddar that needed using. I wasn't in the mood for salad, so I tossed the greens into my blender with some basil from the windowsill and whatever nuts I had left in the pantry. What came out was this vibrant green pesto that smelled like summer, even though it was drizzling outside. I slathered it on bread, added cheese, and made what turned out to be the best grilled cheese I'd had in years.
I made this for my neighbor after she helped me move furniture, and she stood in my kitchen eating it over the sink because she couldn't wait. She kept saying she didn't know spinach could taste like this, all garlicky and rich instead of boring and healthy. We ended up making two more because one sandwich wasn't enough. Now she texts me whenever she has leftover greens, asking if I'm free for a grilled cheese session.
Ingredients
- Fresh spinach leaves: Use the tender baby spinach if you can, it blends smoother and tastes milder than the big tough leaves.
- Fresh basil leaves: This is what makes it smell like pesto instead of just blended spinach, don't skip it even if you only have a handful.
- Grated Parmesan cheese: The real stuff in a wedge you grate yourself has way more flavor than the powdery kind in a shaker.
- Toasted pine nuts: These add a buttery richness, but walnuts work great too and cost less.
- Garlic clove: One large clove is perfect, two makes it punchy, three means you're not kissing anyone later.
- Extra virgin olive oil: This is what turns everything into a smooth paste, use the good stuff since you'll taste it.
- Lemon juice: Just a tablespoon brightens everything up and keeps the pesto from tasting flat.
- Sourdough or country bread: You need something sturdy that won't get soggy under all that pesto and cheese.
- Unsalted butter: Softened butter spreads easier and gives you that golden crispy crust without burning.
- Mozzarella cheese: This is your melt, the cheese that gets all gooey and stretchy when you pull the sandwich apart.
- Sharp cheddar cheese: This is your flavor, it adds a tangy bite that balances the mild mozzarella.
Instructions
- Blend the pesto:
- Toss the spinach, basil, Parmesan, nuts, garlic, salt, and pepper into your food processor and pulse until it looks like green confetti. Then, with the machine running, pour in the olive oil and lemon juice in a steady stream until it turns into a thick, spreadable paste that clings to a spoon.
- Butter your bread:
- Spread softened butter on one side of each slice, this is the side that will touch the pan and get all golden and crispy. Lay them buttered side down on your counter so you can build the sandwiches.
- Assemble the sandwiches:
- Spread a tablespoon of that bright green pesto on the unbuttered side of two slices, then pile on the mozzarella and cheddar. Top with the remaining bread slices, buttered side facing out, and press down gently so everything sticks together.
- Grill until golden:
- Heat your skillet over medium heat and lay the sandwiches in carefully, then cook for 3 to 4 minutes without moving them much until the bottom is deep golden brown. Flip them over, press down gently with your spatula, and cook the other side until the cheese is fully melted and oozing out the edges.
- Cool and serve:
- Let them sit for a minute so you don't burn your mouth on molten cheese, then slice them in half and watch the cheese stretch. Serve them while they're still warm and crispy.
Save The first time I brought these to a potluck, someone asked if I'd ordered them from a cafe because they looked too good to be homemade. I told them it was just a grilled cheese and they didn't believe me until I described the pesto. That sandwich sparked a whole conversation about how we forget that simple food can be special if you add one interesting thing. It made me realize that cooking doesn't have to be complicated to feel like you're sharing something meaningful.
Storing Your Pesto
The pesto keeps in the fridge for about a week if you press plastic wrap directly onto the surface to keep it from browning. I usually make a full batch and use it on pasta, stirred into scrambled eggs, or as a dip for crackers throughout the week. You can also freeze it in ice cube trays and pop out a cube whenever you want to make a quick sandwich or need a flavor boost for roasted vegetables.
Choosing Your Cheese
I like the combination of mozzarella and sharp cheddar because one melts beautifully and the other brings bold flavor, but you can swap in whatever you have. Gruyere makes it fancy, fontina adds a creamy sweetness, and even pepper jack works if you want a little heat. Just make sure at least one of your cheeses is a good melter, or you'll end up with a sandwich that tastes great but doesn't have that satisfying cheese pull.
Making It Your Own
Once you have the basic pesto down, you can play with it endlessly. I've added sun dried tomatoes, tucked in some roasted red peppers, and even thrown arugula into the pesto when I ran out of basil. One time I used everything bagel seasoning on the buttered bread before grilling and it added this salty, garlicky crunch that everyone loved.
- Try adding a smear of fig jam inside for a sweet and savory contrast.
- Use ciabatta or focaccia instead of sourdough for a different texture.
- Toss in a handful of arugula with the cheese for a peppery bite.
Save This sandwich reminds me that sometimes the best meals come from just paying attention to what you have and being willing to try something new. I hope it becomes one of those recipes you make on a whim and end up craving all the time.
Common Recipe Questions
- → Can I make the spinach pesto ahead of time?
Yes, the pesto can be prepared up to 2 days in advance and stored in an airtight container in the refrigerator. This makes assembly even quicker when you're ready to grill.
- → What's the best way to achieve crispy bread?
Butter the bread generously and cook over medium heat without rushing. Press gently with your spatula and allow 3-4 minutes per side for optimal golden-brown color and cheese melt.
- → Can I substitute the cheese blend?
Absolutely. Use any melting cheeses you prefer—try fontina, gruyere, or provolone. The combination of mozzarella and cheddar provides the best balance of flavor and texture.
- → How do I prevent the pesto from making the bread soggy?
Spread the pesto directly onto the bread rather than mixing it with butter, and use only 1 tablespoon per sandwich. The layer of cheese also acts as a barrier.
- → What are good side dishes to serve with this?
A crisp green salad, tomato soup, or roasted vegetables complement this sandwich beautifully. The fresh acidity balances the richness of the melted cheese and pesto.
- → Can I use frozen spinach instead of fresh?
Yes, but thaw and squeeze out excess moisture thoroughly. Frozen spinach tends to be wetter and can dilute the pesto if not properly drained beforehand.