Save I stumbled onto this sandwich on a chilly April morning when I had leftover peas from a failed risotto attempt. Rather than toss them, I blended them with basil from the windowsill and smeared the bright green mess onto sourdough with mozzarella. The first bite was a revelation: sweet, herby, creamy, and nothing like the forgettable grilled cheese I grew up with. My partner wandered into the kitchen, drawn by the smell of browning butter, and declared it the best thing I'd made all month.
The first time I made this for friends, I worried the green would scare them off. Instead, they fought over the last half sandwich and asked for the recipe before they even left. One friend later told me she made it for her kids, who normally refuse anything green, and they devoured it without question. That's when I realized this wasn't just a sandwich, it was a gateway to getting people to eat more vegetables without feeling lectured.
Ingredients
- Fresh or thawed frozen peas: Frozen peas are actually sweeter than most fresh ones because they're picked at peak ripeness, so don't feel bad using them.
- Fresh basil leaves: This is what makes the pesto smell like summer, so use the freshest you can find or grow your own on a sunny sill.
- Garlic clove: One small clove is plenty, I learned the hard way that too much garlic overpowers the delicate pea flavor.
- Grated Parmesan cheese: A little goes a long way for that nutty, salty punch that balances the sweetness of the peas.
- Toasted pine nuts: Toasting them for a few minutes in a dry pan makes them fragrant and golden, adding a buttery crunch.
- Extra virgin olive oil: Use a good one here, it holds everything together and adds richness without being heavy.
- Lemon zest and juice: This brightens the whole pesto and keeps it from tasting flat or muddy.
- Sourdough bread: The tangy crust crisps up beautifully and holds up to the moisture of the pesto without getting soggy.
- Unsalted butter: Softened butter spreads easily and creates that irresistible golden crust when it hits the hot pan.
- Shredded mozzarella cheese: It melts into creamy, stretchy goodness, though fresh mozzarella slices work if you want a fancier texture.
- Baby arugula or spinach: Optional, but it adds a peppery bite and makes you feel like you're eating something virtuous.
Instructions
- Make the Pesto:
- Toss the peas, basil, garlic, Parmesan, pine nuts, olive oil, lemon zest, lemon juice, salt, and pepper into a food processor. Pulse until it's mostly smooth but still has a little texture, you want it spreadable but not baby food.
- Assemble the Sandwiches:
- Butter one side of each slice of sourdough, then lay two slices buttered side down. Spread a generous layer of pesto on the unbuttered side, pile on the mozzarella, tuck in some greens if you like, and top with the remaining bread slices, buttered side up.
- Grill the Sandwiches:
- Heat your skillet over medium heat and set the sandwiches in gently. Cook for 3 to 4 minutes per side, pressing down lightly with a spatula, until the bread is golden and crackling and the cheese is melted and gooey.
- Serve:
- Slice each sandwich in half and serve immediately while the cheese is still stretchy. Pair it with something crisp and cold to drink.
Save One Saturday morning, my neighbor knocked on the door just as I was pulling these off the stove. I offered her half of one, and she stood in my kitchen eating it in silence, then asked if I could teach her how to make it. We ended up spending the afternoon making batch after batch, talking about everything and nothing. That sandwich turned into a friendship I didn't know I needed.
How to Store and Reheat
The pesto keeps in an airtight container in the fridge for up to five days, just drizzle a thin layer of olive oil over the top to prevent browning. Cooked sandwiches are best fresh, but if you have leftovers, wrap them in foil and reheat in a 350 degree oven for about 10 minutes to crisp them back up. I've also frozen leftover pesto in ice cube trays, then popped the cubes into a freezer bag for quick future use.
Substitutions and Variations
If you can't do nuts, swap the pine nuts for sunflower seeds, they toast up just as nicely and add a similar crunch. Whole wheat or gluten free bread works fine if that's what you've got, though sourdough really is the star here. You can also use fontina, provolone, or even a sharp white cheddar if mozzarella isn't your thing. A pinch of red pepper flakes in the pesto adds a gentle heat that plays well with the sweetness of the peas.
Serving Suggestions
This sandwich shines alongside a simple green salad dressed with lemon and olive oil, or a bowl of tomato soup if you're feeling nostalgic. I also love it with a handful of kettle cooked chips and a cold glass of sparkling water with a squeeze of lemon. If you're serving it for brunch, pair it with fresh fruit and a crisp Sauvignon Blanc.
- Serve with a side of roasted cherry tomatoes for extra brightness.
- Add a drizzle of balsamic glaze on top for a tangy finish.
- Cut into small squares and serve as an appetizer at parties.
Save This sandwich has become my go to when I want something comforting but not boring, familiar but a little surprising. I hope it finds a spot in your regular rotation too.
Recipe Guide
- → Can I make the pesto ahead of time?
Yes, absolutely. Prepare the pesto up to 2 days in advance and store it in an airtight container in the refrigerator. Bring it to room temperature before assembling your sandwiches for best flavor.
- → What's the best way to prevent the bread from burning?
Use medium heat rather than high, and press gently on the sandwich while cooking. This ensures the bread toasts to golden brown while giving the cheese sufficient time to melt completely.
- → Can I use frozen peas for the pesto?
Thawed frozen peas work perfectly and often provide excellent texture. Drain them well and pat dry before blending to avoid excess moisture that could dilute your pesto.
- → What are good substitutes for pine nuts?
Walnuts, sunflower seeds, or pumpkin seeds all work wonderfully. Each brings its own nutty character. For nut-free options, sunflower seeds provide similar richness without the allergen concerns.
- → How do I get the cheese to melt evenly?
Shred the mozzarella for faster, more even melting compared to sliced cheese. Cook on medium heat and don't rush the process. For thicker, creamier melts, consider using fresh mozzarella slices slightly pressed between layers.
- → Can this be made gluten-free?
Yes. Substitute your favorite gluten-free bread and the rest of the ingredients remain unchanged. Gluten-free sourdough or artisan loaves work particularly well and maintain the texture you're after.