Spinach Pesto Grilled Cheese

My neighbor knocked on my door one afternoon holding a grocery bag full of spinach from her garden, way more than she could use. I wasn't about to let it wilt in my fridge, so I tossed it into pesto with some basil and smeared it onto a grilled cheese. The first bite was a revelation: earthy, garlicky, and ridiculously comforting. Now I make it whenever I want something familiar with a little edge.

I made this for my sister one rainy Saturday when she showed up unannounced and starving. She sat at the counter, watched me blend the pesto, and declared it the best thing I'd made in months. We ate the sandwiches standing up, cheese still oozing, barely talking because we were too busy chewing. That's the kind of meal this is: simple, but it stops conversation.

Ingredients

• Fresh spinach leaves: Packed cups are key here, don't just loosely fill the measuring cup or your pesto will taste watery instead of vibrant.
• Fresh basil leaves: Basil adds that classic pesto brightness and keeps the spinach from feeling too vegetal or one note.
• Grated Parmesan cheese: Use the real stuff, not the shelf stable kind, it makes the pesto taste nutty and rich instead of salty and flat.
• Toasted pine nuts: Toasting them in a dry skillet for a few minutes brings out a buttery sweetness that balances the garlic.
• Garlic clove: One large clove is plenty, more than that and it can overpower the greens and make your breath unbearable.
• Extra virgin olive oil: This is what makes the pesto silky and luscious, so use one you actually like the taste of.
• Lemon juice: Just a tablespoon brightens everything and keeps the pesto from tasting too heavy or oily.
• Sourdough or country bread: You want something sturdy with a bit of chew, soft sandwich bread will get soggy and fall apart.
• Unsalted butter: Softened butter spreads easily and crisps up the bread beautifully without burning.
• Mozzarella cheese: This is your melt factor, it gets gooey and stretchy and holds the sandwich together.
• Sharp cheddar cheese: Cheddar adds a punch of flavor so the sandwich doesn't taste bland or too mild.

Instructions

Blend the pesto:

Toss spinach, basil, Parmesan, pine nuts, garlic, salt, and pepper into your food processor and pulse until everything is finely chopped and starting to clump together. With the motor running, slowly drizzle in the olive oil and lemon juice until you get a smooth, spreadable paste that clings to a spoon.

Butter the bread:

Spread softened butter on one side of each slice of bread, this is the side that will touch the pan and get golden and crispy. Lay them buttered side down on your counter or cutting board so you can build the sandwiches.

Assemble the sandwiches:

Spread a tablespoon of pesto on the unbuttered side of two slices, then pile on half the mozzarella and cheddar. Top with the remaining bread slices, buttered side facing out, and press gently so everything sticks together.

Grill until golden:

Heat a large skillet over medium heat and place the sandwiches in the pan. Cook for 3 to 4 minutes per side, pressing down gently with a spatula, until the bread is deeply golden and the cheese is fully melted and oozing out the sides.

Cool and serve:

Let the sandwiches sit for a minute or two before slicing so the cheese doesn't all run out. Cut in half and serve while still warm and crispy.

Save

The first time I brought this to a potluck, someone asked if I'd ordered it from a cafe. I laughed and told them it was just spinach pesto and cheese, but they didn't believe me until I wrote down the recipe. It's funny how a few good ingredients and a hot pan can make something feel special enough to share.

What to Do with Leftover Pesto

You'll have extra pesto after making two sandwiches, and that's a gift. I stir it into scrambled eggs, toss it with hot pasta and cherry tomatoes, or spread it on crackers with a little goat cheese. It keeps in the fridge for about a week if you press plastic wrap directly onto the surface to keep it from browning. You can also freeze it in an ice cube tray and pop out a cube whenever you need a hit of green, garlicky goodness.

How to Make It Your Own

This sandwich is a template, not a rule. I've added roasted red peppers, sliced tomatoes, and even leftover grilled chicken when I wanted something heartier. Some people like to swap in Gruyere or fontina for a nuttier, creamier melt. If you're feeling fancy, sprinkle a little grated Parmesan on the outside of the bread before it hits the pan, it forms a crispy, salty crust that makes the whole thing taste like it came from a bistro.

Serving Suggestions and Pairings

This sandwich is rich and satisfying, so I like to serve it with something light and bright to balance it out. A simple arugula salad with lemon vinaigrette cuts through the cheese, or a bowl of tomato soup for dipping makes it feel like the coziest lunch ever. If you're feeding a crowd, slice the sandwiches into triangles and serve them as appetizers with a little extra pesto on the side for dipping.

• Pair with a crisp white wine or a cold beer if you're having it for dinner.
• Serve alongside pickles or a handful of chips for crunch and contrast.
• Leftovers reheat well in a skillet, just cover with a lid to help the cheese melt again.

Save

This sandwich has become my go to when I want something comforting but not boring, familiar but a little surprising. I hope it lands on your table on a day when you need exactly that.

Recipe FAQs

→ Can I make the pesto ahead of time?

Yes, prepare the spinach pesto up to 2 days in advance and store it in an airtight container in the refrigerator. You can also freeze it for up to 3 months in ice cube trays for convenient portions.

→ What bread works best for this sandwich?

Sourdough and country bread are ideal because they develop a crispy exterior while staying tender inside. Other good options include ciabatta, focaccia, or thick-cut white bread.

→ How do I prevent the cheese from leaking out?

Ensure your bread slices are thick enough and press gently during cooking. Don't overstuff the sandwich, and keep your skillet at medium heat so the cheese melts gradually rather than rapidly oozing out.

→ Can I substitute the cheese combination?

Absolutely. You can use any melting cheese like Swiss, provolone, fontina, or Gruyère. Keep the total cheese amount around 6 ounces for the best melting consistency.

→ What's the best way to achieve extra crispy bread?

Spread a thin layer of softened butter on both outer sides of the bread before grilling. For extra crispiness, sprinkle Parmesan cheese on the buttered exterior and let it toast into the bread.

→ Are there dairy-free alternatives for this sandwich?

Yes, use dairy-free butter and vegan cheese alternatives for grilling. For the pesto, substitute nutritional yeast or vegan Parmesan, and use olive oil instead of traditional dairy-based options.