Pin My neighbor dropped off a bag of spinach from her garden one Saturday morning, and I stared at it wondering what to do besides the usual salad. I had basil on the windowsill and some pine nuts left over from a pasta experiment. Within twenty minutes, I had a vivid green pesto that smelled like summer, and the only logical next step was to slather it inside a grilled cheese. That first bite, with the sharp cheddar mingling with the herbaceous pesto, made me wish I'd thought of it years ago.
I made this for my sister after she'd had a rough week at work, and she ate it standing at the counter, eyes closed, savoring every bite. She asked for the recipe twice before she even finished her sandwich. It became our Friday tradition for a while, each time tweaking the cheese blend or adding a slice of tomato. Those quiet kitchen moments, hearing the sizzle and smelling the butter toast the bread, reminded me how a simple sandwich can be a small act of care.
Ingredients
- Fresh spinach leaves: Two packed cups give the pesto its vibrant green color and mild, earthy base without overpowering the basil.
- Fresh basil leaves: Half a cup adds that classic pesto fragrance and a slightly sweet, peppery note that balances the spinach.
- Grated Parmesan cheese: A quarter cup brings salty, nutty depth and helps the pesto cling together beautifully.
- Toasted pine nuts: A quarter cup lends a buttery richness, though walnuts work just as well if you want a more robust flavor.
- Large garlic clove: One clove gives the pesto its signature bite, but use two if you love garlic as much as I do.
- Extra virgin olive oil: A third of a cup creates a smooth, spreadable texture and carries all the flavors together.
- Salt and black pepper: Half a teaspoon of salt and a quarter teaspoon of pepper season the pesto just right, but always taste and adjust.
- Lemon juice: One tablespoon brightens the whole blend and keeps the greens from tasting flat.
- Sourdough or country bread: Four slices with a sturdy crumb hold up to the pesto and butter without getting soggy.
- Unsalted butter: Four tablespoons, softened, spread easily and toast the bread to a perfect golden crisp.
- Mozzarella cheese: Four ounces melt into gooey, stretchy goodness that makes every bite satisfying.
- Sharp cheddar cheese: Two ounces add a tangy punch that cuts through the richness and pairs beautifully with the pesto.
- Prepared spinach pesto: Two tablespoons per sandwich is just enough to coat each bite without overwhelming the cheese.
Instructions
- Make the vibrant pesto:
- Toss the spinach, basil, Parmesan, pine nuts, garlic, salt, and pepper into your food processor and pulse until everything is finely chopped and fragrant. With the motor running, pour in the olive oil and lemon juice in a slow, steady stream until the mixture becomes a smooth, spreadable paste that clings to the back of a spoon.
- Butter the bread:
- Spread softened butter generously on one side of each slice of bread, making sure to reach the edges so every corner gets crispy. Lay them buttered side down on your counter or cutting board.
- Layer the pesto and cheese:
- Spread one tablespoon of that bright green pesto on the unbuttered side of two slices, then pile on half the mozzarella and cheddar on each. Top with the remaining bread slices, buttered side facing out, pressing gently so everything holds together.
- Toast to golden perfection:
- Heat a large skillet or griddle over medium heat and lay your sandwiches in carefully. Cook for three to four minutes on each side, pressing down lightly with a spatula, until the bread turns a beautiful golden brown and the cheese melts into gooey strands.
- Rest and serve:
- Let the sandwiches cool for a minute or two so the cheese sets just enough to stay put when you slice. Cut them in half and serve while they are still warm and fragrant.
Pin 
One afternoon, I served these sandwiches at a casual lunch with friends, and we ended up sitting outside on the porch, the plates balanced on our laps, talking and laughing for hours. Someone said it tasted like spring in sandwich form, and I couldn't think of a better description. It wasn't just the food, but the way it brought us all together over something simple and delicious that made the day memorable.
Making the Pesto Ahead
The pesto keeps beautifully in the fridge for up to a week if you store it in an airtight container with a thin layer of olive oil on top to prevent browning. I often make a double batch and use it on pasta, stirred into scrambled eggs, or as a dip for crackers. Freezing it in ice cube trays is another trick I picked up, so you always have a little burst of green flavor ready to go whenever inspiration strikes.
Choosing Your Cheese
Mozzarella gives you that stretchy, gooey pull, while sharp cheddar adds a tangy contrast that balances the richness of the pesto. I have tried Gruyere for a nuttier flavor and fontina for something creamy and mild, and both were wonderful. Play around with what you have on hand or what you love most, because the pesto is forgiving and pairs well with almost any melting cheese you can think of.
Serving Suggestions and Add Ins
This sandwich is perfect on its own, but I love pairing it with a simple arugula salad dressed with lemon and olive oil or a bowl of creamy tomato soup for dipping. Sometimes I tuck in a few slices of ripe tomato or roasted red pepper before grilling for extra sweetness and color. If you want a little crunch, a handful of baby spinach or arugula inside the sandwich adds a fresh, peppery bite that complements the pesto beautifully.
- Serve alongside a crisp green salad or a cup of tomato soup for a cozy, complete meal.
- Add sliced tomato, roasted red pepper, or fresh greens inside for extra flavor and texture.
- Sprinkle a little grated Parmesan on the outside of the bread before grilling for an extra crispy, cheesy crust.
Pin This grilled cheese has become my go to whenever I want something comforting but a little more interesting than the usual. I hope it brings you as much joy as it has brought me, one crispy, cheesy, herbaceous bite at a time.
Recipe Questions & Answers
- → Can I make the spinach pesto ahead of time?
Yes, you can prepare the pesto up to 3 days in advance. Store it in an airtight container in the refrigerator, or freeze it for up to a month. This makes weeknight preparation even faster.
- → What's the best bread to use for this sandwich?
Sourdough or country bread works beautifully due to their sturdy texture and subtle tang. Brioche, whole wheat, or Italian bread are excellent alternatives if you prefer different flavors.
- → How do I prevent the bread from burning while the cheese melts?
Use medium heat rather than high heat, and cover the skillet with a lid for the last minute of cooking. This traps steam to melt the cheese while keeping the bread from darkening too quickly.
- → Can I substitute the pine nuts in the pesto?
Absolutely. Walnuts, almonds, or sunflower seeds work great. For a nut-free version, use roasted sunflower or pumpkin seeds for similar texture and richness.
- → What are good additions to elevate this sandwich?
Sliced tomato, roasted red peppers, caramelized onions, or fresh arugula add delicious depth. A thin layer of ricotta or cream cheese before spreading pesto creates extra creaminess.