10-Minute Tuna Pesto Mozzarella Melt Panini

Why You’ll Love This Recipe

• Fast comfort food: crisp bread, melty mozzarella, and savory pesto in about 10 minutes.
• Pantry-friendly: canned tuna and pesto do most of the work.
• No panini press needed: a skillet and a little pressure gets you that toasted, pressed texture.
• Flexible: use tuna salad, plain tuna, add tomato, or swap cheeses with what you have.

Grocery List

• Produce: 1 small tomato (optional), 1 lemon (optional)
• Dairy: mozzarella (4 ounces), unsalted butter (1 tablespoon)
• Pantry: canned tuna (1 can, 5 ounces), basil pesto (4 tablespoons), mayonnaise (2 tablespoons), sturdy sliced bread (4 slices), kosher salt, black pepper

Full Ingredients

For the tuna filling

• 1 (5-ounce) can tuna in water, drained well
• 2 tablespoons mayonnaise
• 1 teaspoon lemon juice (optional but recommended for brightness)
• 1/8 teaspoon kosher salt
• 1/8 teaspoon black pepper

For assembling the sandwiches

• 4 slices sturdy bread (sourdough or ciabatta), about 1/2-inch thick
• 4 tablespoons basil pesto (1 tablespoon per slice)
• 4 ounces mozzarella (about 1 cup shredded low-moisture mozzarella, or 4 ounces sliced fresh mozzarella)
• 4 thin tomato slices (optional)

For skillet “pressing”

• 1 tablespoon unsalted butter (or 2 teaspoons olive oil)

Step-by-Step Instructions

Step 1: Drain the tuna and mix a quick tuna salad

Open 1 (5-ounce) can tuna and drain it very well (extra liquid can make the sandwich soggy). In a small bowl, mix the tuna with 2 tablespoons mayonnaise, 1 teaspoon lemon juice (if using), 1/8 teaspoon kosher salt, and 1/8 teaspoon black pepper. Break up any large chunks so it spreads evenly.

Step 2: Prep the bread with pesto

Lay out 4 slices of bread. Spread 1 tablespoon pesto on one side of each slice. This pesto layer is the flavor backbone, so aim for full coverage all the way to the edges.

Step 3: Build the sandwiches in the right order

Flip 2 slices so the pesto side faces up. Divide the tuna mixture evenly between them and spread into an even layer.

Add mozzarella on top: use about 2 ounces per sandwich (half the cheese). If using tomato slices, add 2 thin slices per sandwich on top of the cheese (or tuck them between tuna and cheese if you want them less juicy).

Top with the remaining bread slices, placing them pesto side down so pesto is on the inside of both sides of the sandwich.

Step 4: Heat the skillet gently for a crisp outside and melty inside

Place a large skillet over medium-low heat for 1 minute to preheat. Add 1 tablespoon butter and let it melt and coat the pan (or add 2 teaspoons olive oil).

Why medium-low? It gives the mozzarella time to melt before the bread over-browns.

Step 5: Start toasting and press the sandwiches

Set the sandwiches in the skillet. Immediately press them down firmly with a sturdy spatula. For a stronger “panini” effect, place a second smaller skillet or a heavy pot on top (carefully) to weigh them down.

Cook on the first side for 3 minutes, pressing occasionally so the bread makes full contact with the skillet. You’re looking for a deep golden-brown crust.

Step 6: Flip, press again, and finish melting

Flip the sandwiches and cook for another 3 minutes, still over medium-low heat. Press again to encourage a crisp exterior and a gooey center.

If your bread is browning too fast, reduce the heat to low. If the cheese needs more time, cook an additional 1 minute per side on low.

Step 7: Rest briefly, slice, and serve

Transfer sandwiches to a cutting board and let them rest for 1 minute. This helps the cheese settle slightly so the filling doesn’t slide out when you cut.

Slice in half and serve right away while the mozzarella is stretchy and the pesto is warm and fragrant.

Pro Tips

• Prevent sogginess: Drain tuna thoroughly, and if using tomato, slice it thin and blot it with a paper towel.
• Cheese choice matters: Shredded low-moisture mozzarella melts evenly; fresh mozzarella is extra gooey but can release more moisture.
• Keep the heat lower than you think: Medium-low is the sweet spot for melty cheese and crisp bread without scorching.
• Get a real “press” without a panini maker: Put a second skillet on top (or a pot) and press lightly; don’t crush the sandwich.
• Extra flavor boost: Add 1 teaspoon Dijon to the tuna mixture (if you like a little tang).

Variations

• Tuna pesto melt with tomatoes and balsamic: Add tomato slices and a very light drizzle (about 1 teaspoon per sandwich) of balsamic glaze after cooking.
• Spicy tuna pesto melt: Mix 1 teaspoon Calabrian chili paste or 1/2 teaspoon crushed red pepper into the tuna mixture.
• Different cheese: Swap mozzarella for provolone (same amount) for a sharper, deli-style melt.

Storage & Make-Ahead

This sandwich is best eaten immediately for maximum crispness. If you want to prep ahead, mix the tuna filling up to 2 days in advance and store it in an airtight container in the refrigerator. Assemble and cook right before eating. Leftover cooked sandwiches can be refrigerated for up to 1 day; reheat in a dry skillet over low heat for 2–3 minutes per side (microwaving softens the bread).

Nutrition (per serving)

Approximate per serving (1 sandwich): 620 calories, 34 g protein, 34 g fat, 44 g carbohydrates, 3 g fiber, 950 mg sodium. Values vary by bread, pesto, and cheese brands.