Roasted Tomato Pesto Grilled Cheese

My neighbor showed up one rainy Tuesday with a jar of homemade pesto and a bag of tomatoes from her garden. I had sourdough going stale on the counter and mozzarella that needed using, so I tossed the tomatoes in the oven and forgot about them for an hour. When I finally remembered, they had turned into these sweet, jammy rounds that smelled like summer concentrated into coins. That accidental slow roast became the backbone of what I now make whenever I need something comforting but a little special.

I made this for my teenage niece who claimed she hated anything green. She eyed the pesto suspiciously, picked at the crust, then devoured both halves without a word. Ten minutes later she texted me asking for the recipe. Sometimes the best compliment is silence followed by a clean plate and a request to make it again.

Ingredients

• Ripe tomatoes: Look for tomatoes that give slightly when pressed, they roast down into concentrated sweetness and their natural sugars caramelize beautifully at low heat.
• Olive oil: A good drizzle helps the tomatoes blister and brown without drying out, plus it carries the oregano flavor into every bite.
• Sea salt and black pepper: These wake up the tomato flavor during roasting, drawing out moisture and intensifying their natural taste.
• Dried oregano: A small pinch adds an earthy, aromatic note that bridges the Italian and American sides of this sandwich.
• Rustic sourdough bread: The sturdy crumb holds up to all the melted cheese and juicy tomatoes without falling apart, and the tang complements the pesto.
• Unsalted butter: Softened butter spreads easily and creates that golden, crispy crust when it hits the hot pan.
• Basil pesto: This is where the herbal brightness lives, cutting through richness and adding a garlicky punch that makes every bite more interesting.
• Mozzarella cheese: It melts into creamy, stretchy ribbons and provides a mild base that lets the other flavors shine.
• Sharp cheddar cheese: The sharpness adds depth and a slight tang that balances the sweetness of roasted tomatoes.
• Baby spinach or arugula: Optional but wonderful, adding a peppery freshness and a little green to the gooey interior.

Instructions

Get the oven ready:

Preheat your oven to 300°F and line a baking sheet with parchment so the tomatoes do not stick. This low temperature is key, it coaxes out sweetness without scorching.

Prepare the tomatoes:

Lay the tomato slices in a single layer, drizzle with olive oil, and sprinkle with salt, pepper, and oregano. Roast for 50 to 60 minutes, flipping them halfway so both sides caramelize evenly, until they are deeply golden and smell like concentrated sunshine.

Butter the bread:

Spread softened butter on one side of each slice, this is the side that will touch the pan and turn golden and crispy. Set two slices buttered side down on your counter.

Build the sandwiches:

Spread a tablespoon of pesto on the unbuttered side of each bread slice, then layer with mozzarella, roasted tomatoes, cheddar, and a handful of greens if using. Top with the remaining bread slices, buttered side facing up.

Cook low and slow:

Heat a large skillet over medium low heat, add the sandwiches, and cook for 4 to 5 minutes per side, pressing gently with a spatula. You want the cheese fully melted and the bread deeply golden, not burnt.

Serve hot:

Slice each sandwich in half while the cheese is still molten and stretchy. Serve immediately, maybe with a handful of greens on the side or a bowl of soup.

Save

One winter evening I served these at a small dinner party, and we ended up standing around the stove making batch after batch because no one wanted to sit down. The kitchen smelled like garlic and butter, and everyone had cheese on their fingers. That night taught me that the best meals are the ones you eat standing up, laughing, with a spatula still in your hand.

Choosing Your Cheese

I have tried this sandwich with at least a dozen cheese combinations, and the mix of mozzarella and sharp cheddar remains my favorite for its balance of stretch and flavor. Smoked gouda adds a campfire depth that pairs beautifully with the roasted tomatoes, while gruyere brings a nutty sweetness that feels a little more elegant. Fontina melts like a dream and has a mild earthiness, and provolone keeps things classic with a slight tang. Play with what you have, but always use at least two types so you get both melt and taste.

Making It Your Own

Some nights I add a smear of sun dried tomato pesto for extra intensity, or a pinch of red pepper flakes if I want a gentle kick of heat. A drizzle of balsamic glaze right before serving adds a sweet acidity that makes the whole thing sing. I have also tucked in thin slices of prosciutto for guests who wanted meat, and it worked beautifully without overwhelming the other flavors. This sandwich is forgiving and loves improvisation, so trust your instincts and use what makes you happy.

Pairing and Serving

This sandwich is rich enough to be a meal on its own, but I almost always serve it with something crisp and light to balance the gooey cheese. A simple arugula salad with lemon and olive oil cuts through the richness, or a cup of tomato soup turns it into a cozy, nostalgic lunch. On warmer days, I pair it with pickles or a handful of kettle chips for crunch. If you are feeding a crowd, cut the sandwiches into quarters and serve them as appetizers, they disappear fast.

• Serve with a bright green salad dressed in lemon vinaigrette to balance the richness.
• A bowl of creamy tomato soup alongside turns this into the ultimate comfort meal.
• Cut into small squares for a party platter that will vanish before you finish plating.

Save

This sandwich has become my answer to gray afternoons and unexpected guests, proof that a few good ingredients and a little patience can turn something simple into something you will crave again and again. I hope it finds a place in your kitchen the way it has in mine.

Recipe FAQ Section

→ How long should I roast the tomatoes?

Roast tomatoes at 300°F for 50-60 minutes, flipping halfway through. They should be deeply caramelized but still hold their shape. This low-and-slow method concentrates their natural sweetness and creates intense flavor.

→ Can I prepare the roasted tomatoes in advance?

Yes, roast the tomatoes up to 2 days ahead and store them in an airtight container in the refrigerator. You can also freeze them for up to 1 month. Let them come to room temperature before assembling your sandwich.

→ What's the best way to prevent soggy bread?

Use sturdy rustic sourdough or country bread with a thick crust. Apply pesto on the inner bread surface as a moisture barrier. Ensure tomatoes are cooled before assembling to prevent steam from soaking the bread.

→ Can I use a different cheese combination?

Absolutely. Experiment with smoked gouda, gruyère, fontina, provolone, or aged cheddar. Using two complementary cheeses creates complexity—pair a creamy cheese with a sharp one for balanced flavor and texture.

→ How do I get the cheese completely melted?

Cook on medium-low heat for 4-5 minutes per side, pressing gently with a spatula. Cover the skillet with a lid or foil during cooking to trap steam and melt the cheese more efficiently without over-browning the bread.

→ Is this suitable for dietary restrictions?

This is naturally vegetarian. Use gluten-free bread for a gluten-free version. Check pesto ingredients for allergens like nuts and dairy. Substitute vegan butter and plant-based cheese for a dairy-free option.