Grilled Chicken Spinach Panini

There was a Wednesday afternoon when I had leftover grilled chicken and nothing but spinach wilting in the crisper. I buttered some bread with garlic I'd minced too much of the night before, piled everything between two slices, and pressed it all down in a hot skillet. The smell that filled the kitchen—toasted butter, melting cheese, that slight bitterness from the spinach—made me forget I was just trying to use up leftovers. That panini became my go-to whenever I need something fast, warm, and satisfying without much fuss.

I made these for my sister and her kids one Saturday when they stopped by unannounced. The kids kept asking what smelled so good, and when I sliced the paninis in half, the cheese stretched between the halves like something out of a commercial. My sister laughed and said I should open a café, but honestly, it was just good timing and a hot press doing all the work.

Ingredients

• Boneless, skinless chicken breasts: These grill quickly and slice thin, which is exactly what you need for a panini that holds together without falling apart when you bite into it.
• Olive oil: Brushing the chicken with this keeps it from sticking to the grill and adds a subtle richness that pairs well with the garlic butter later.
• Salt, black pepper, and dried Italian herbs: Simple seasoning that doesn't fight with the other flavors, just builds a solid base for everything else to shine.
• Unsalted butter: Softened butter is key because it spreads easily and doesn't tear the bread, plus you control the salt level this way.
• Garlic cloves: Freshly minced garlic in the butter makes all the difference; the jarred stuff just doesn't have that same sharp, aromatic punch.
• Fresh parsley: Finely chopped parsley brightens the garlic butter and adds a tiny pop of color that makes the whole sandwich feel more alive.
• Rustic Italian or sourdough bread: You want something sturdy with a good crust that can stand up to the press without getting soggy or falling apart.
• Fresh baby spinach: It wilts down to almost nothing but adds a slight bitterness and texture that balances the richness of the cheese.
• Shredded mozzarella or provolone: Mozzarella melts beautifully and pulls apart in those long, satisfying strings; provolone adds a bit more sharpness if you prefer.
• Grated Parmesan cheese: This adds a salty, nutty layer that makes the cheese blend more complex and keeps it from being one-note.

Instructions

Preheat the grill:

Get your grill pan or outdoor grill to medium-high heat so it's ready to sear the chicken with those nice charred lines. You want it hot enough to cook through without drying out the meat.

Season and grill the chicken:

Brush the chicken breasts with olive oil, sprinkle on the salt, pepper, and Italian herbs, then grill for 5 to 6 minutes per side until the juices run clear. Let them rest for 5 minutes before slicing thinly so the moisture stays inside.

Make the garlic butter:

In a small bowl, mix the softened butter with minced garlic and chopped parsley until it's smooth and evenly combined. This will be your secret weapon for flavor and crunch.

Assemble the sandwiches:

Lay out your bread slices and spread garlic butter on one side of each. On the unbuttered side of four slices, layer the sliced chicken, fresh spinach, mozzarella, and Parmesan, then top with the remaining slices, buttered side facing out.

Press and cook:

Heat your panini press or a large skillet over medium heat, place the sandwiches inside, and press down if using a skillet with a heavy pan. Cook for 3 to 5 minutes per side until the bread is golden and the cheese has melted into gooey perfection.

Slice and serve:

Cut each panini in half while it's still hot so you get that satisfying cheese pull. Serve immediately while the bread is crispy and the inside is warm.

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One evening I made these for a friend who'd had a rough week at work, and we sat on the porch with our paninis and iced tea, not saying much. She took a bite, closed her eyes, and just nodded. Sometimes food doesn't need to be fancy or complicated to remind someone that things can be okay again.

Making It Your Own

If you want to switch things up, try using turkey breast instead of chicken, or add a layer of sliced tomatoes or roasted red peppers for a little sweetness and acidity. I've also thrown in some caramelized onions when I had extra sitting in the fridge, and it added this deep, savory note that made the whole thing feel almost restaurant-quality. The beauty of a panini is that it's forgiving and flexible, so don't be afraid to experiment with what you have on hand.

Serving Suggestions

These paninis are hearty enough to stand on their own, but I usually serve them with a simple green salad dressed in lemon vinaigrette or a bowl of tomato soup for dipping. The contrast between the hot, crispy sandwich and something cool and tangy or warm and smooth makes the meal feel more complete. If you're feeding a crowd, slice each panini into smaller pieces and serve them as appetizers—they disappear fast.

Storage and Reheating

Honestly, these are best eaten fresh, but if you have leftovers, wrap them tightly in foil and store them in the fridge for up to two days. When you're ready to reheat, warm them in a skillet over medium heat rather than the microwave so the bread stays crispy instead of turning rubbery. You can also grill the chicken ahead of time and keep it in the fridge, then just assemble and press the paninis when you're ready to eat.

• Wrap leftovers tightly in foil to keep them from drying out in the fridge.
• Reheat in a skillet or panini press to bring back the crispiness, not the microwave.
• Grill extra chicken and store it separately so you can make fresh paninis throughout the week without starting from scratch.

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This panini has become one of those recipes I make without thinking, the kind that feels like muscle memory now. I hope it becomes that for you too—something easy, comforting, and always worth making.

Recipe FAQs

→ How do I know when the chicken is fully cooked?

Grill chicken breasts for 5-6 minutes per side until the internal temperature reaches 165°F (74°C). The meat should be opaque throughout with no pink inside. Let it rest for 5 minutes before slicing to retain juices.

→ Can I prepare the panini ahead of time?

You can assemble the sandwiches up to 2 hours before grilling. Wrap them in plastic wrap and refrigerate. Add 1-2 minutes to the cooking time if grilling from cold. Do not prepare more than 2 hours in advance as the bread may become soggy.

→ What's the best way to press the panini?

A dedicated panini press delivers the most consistent results. If you don't have one, use a large skillet with a heavy pan, cast iron skillet, or even a foil-wrapped brick placed on top. Apply gentle pressure for even toasting without squishing out the filling.

→ Can I substitute the cheeses?

Absolutely. Provolone works beautifully instead of mozzarella. You can also use fontina, asiago, or a mix of Italian cheeses. Avoid soft cheeses that won't melt properly. The combination should total about 2 cups for best melting.

→ What vegetables can I add to enhance the flavor?

Roasted red peppers, sun-dried tomatoes, and thinly sliced fresh tomatoes work wonderfully. Caramelized onions add sweetness, while arugula or basil leaves provide fresh herbaceous notes. Add these layers between the spinach and cheese for best distribution.

→ How should I store leftovers?

Enjoy panini fresh for the best texture. Leftovers can be refrigerated in an airtight container for up to 2 days. Reheat gently in a skillet or panini press over medium heat for 2-3 minutes to restore crispness without drying out the chicken.