Grilled Chicken Spinach Panini

There was a Tuesday afternoon when I had leftover grilled chicken and no plan for dinner. I spotted spinach wilting in the crisper and a chunk of mozzarella that needed using. Instead of reheating boring leftovers, I made a panini that turned into one of those meals you crave on repeat. The garlic butter soaking into the bread while it pressed into crispy, golden ridges was the kind of accidental brilliance that happens when youre just trying to use what you have.

I started making these on weekends when friends would drop by unexpectedly. Theres something about a hot, melty sandwich that makes people settle in and stay awhile. One time I made six of them in a row, assembly line style, and everyone stood around the counter eating them straight off the press. The smell of garlic butter and toasted bread filled the whole house, and I remember thinking this is exactly the kind of food that makes a kitchen feel alive.

Ingredients

• Boneless, skinless chicken breasts: I always flatten them slightly with my palm before grilling so they cook evenly and stay juicy, no one wants dry chicken in a panini.
• Olive oil: A light coating keeps the chicken from sticking and helps the seasonings cling, plus it adds a subtle richness that butter alone cant achieve.
• Salt, black pepper, and dried Italian herbs: This simple trio is all you need to make the chicken taste intentional, not bland.
• Unsalted butter: Softened butter spreads easily and lets you control the salt level, especially when youre adding Parmesan later.
• Garlic cloves: Fresh garlic makes all the difference here, the jarred stuff just doesnt have the same punch or aroma.
• Fresh parsley: It brightens the garlic butter and adds a hint of color, making the whole thing feel a little less heavy.
• Rustic Italian or sourdough bread: You want something sturdy enough to hold up under pressure without turning into mush, soft sandwich bread will fall apart.
• Fresh baby spinach: Make sure its completely dry or it will steam the bread instead of crisping it, I learned that the soggy way.
• Shredded mozzarella cheese: It melts beautifully and creates those stretchy cheese pulls that make every bite satisfying.
• Grated Parmesan cheese: This adds a salty, nutty depth that mozzarella alone cant deliver, dont skip it.

Instructions

Preheat the Grill:

Get your grill pan or outdoor grill nice and hot over medium high heat. You want to hear that sizzle the moment the chicken touches the surface.

Season and Grill the Chicken:

Brush the chicken breasts with olive oil, then season both sides with salt, pepper, and Italian herbs. Grill for 5 to 6 minutes per side until the internal temperature hits 165 degrees, then let it rest for 5 minutes before slicing thinly against the grain.

Make the Garlic Butter:

In a small bowl, mix the softened butter with minced garlic and chopped parsley until its smooth and fragrant. This is the secret weapon that makes the bread irresistible.

Assemble the Panini:

Lay out all 8 slices of bread and spread garlic butter on one side of each slice. On the unbuttered side of 4 slices, layer the sliced chicken, spinach, mozzarella, and Parmesan, then top with the remaining bread slices with the buttered side facing out.

Press and Cook:

Heat your panini press or a large skillet over medium heat. Place the sandwiches in the press, or if using a skillet, set a heavy pan on top to weigh them down. Cook for 3 to 5 minutes per side until the bread is golden brown and the cheese is melted and gooey.

Slice and Serve:

Cut each panini in half diagonally and serve immediately while the cheese is still stretchy and the bread is warm and crisp.

Save

One evening I made these for my neighbor who had just moved in and didnt have her kitchen set up yet. She sat at my counter and ate two halves while telling me about her old apartment, and by the time she left, we had plans for coffee the next week. Its funny how a simple sandwich can be the start of something, a friendship, a tradition, a reason to slow down and share a meal.

What to Serve With Your Panini

I usually keep it simple with a handful of mixed greens tossed in lemon juice and olive oil, or a cup of tomato soup if the weather is cool. Sometimes I slice up a crisp apple or pear on the side for a little sweetness that cuts through the richness of the cheese. If Im feeding a crowd, I set out a bowl of kettle chips and let people help themselves, it feels casual and takes the pressure off making everything perfect.

How to Store and Reheat Leftovers

Honestly, these are best eaten fresh, but if you have leftovers, wrap them tightly in foil and keep them in the fridge for up to two days. To reheat, I skip the microwave completely, it makes the bread rubbery. Instead, I warm them in a skillet over low heat for a few minutes on each side until the cheese softens again and the bread crisps back up. You wont get the exact same texture as fresh, but its still pretty satisfying.

Ways to Switch It Up

Sometimes I swap the mozzarella for provolone or fontina if I want a sharper flavor, or I add a few slices of roasted red pepper for a smoky sweetness. If I have leftover pesto, Ill spread a thin layer on the inside before adding the fillings, it adds an herby richness that pairs beautifully with the spinach. You can also use turkey instead of chicken, or even skip the meat entirely and load it up with sauteed mushrooms and caramelized onions for a vegetarian version that still feels hearty.

• Try adding a smear of sun dried tomato spread for a tangy, savory kick.
• Use ciabatta or focaccia for a different texture, both hold up well under pressure.
• If you like heat, sprinkle red pepper flakes into the garlic butter or tuck a few pepperoncini slices inside.

Save

This panini has become one of those recipes I make without thinking, the kind where my hands know what to do before my brain catches up. I hope it becomes that easy and comforting for you too.

Recipe Questions

→ Can I prepare the panini ahead of time?

Yes, you can assemble the panini up to 2 hours before cooking. Wrap tightly in plastic wrap and refrigerate. Cook directly from the refrigerator, adding 1-2 extra minutes to the cooking time.

→ What's the best way to grill the chicken evenly?

For even cooking, pound the chicken breasts to uniform thickness before grilling. This ensures they cook in the same time and stay juicy. Cook over medium-high heat for 5-6 minutes per side until the internal temperature reaches 165°F.

→ Can I use a regular skillet instead of a panini press?

Absolutely. Heat a large skillet over medium heat and place the panini inside. Use a heavy cast-iron skillet or another heavy pan placed on top to weigh it down. Cook 3-5 minutes per side until golden brown.

→ What cheese works best for this panini?

Mozzarella and Parmesan are classic choices that melt beautifully. You can also use provolone, fontina, or a mix of Italian cheeses. Choose cheese that melts easily for the best texture and flavor.

→ How do I prevent the bread from getting too dark?

Use medium heat rather than high heat and monitor the panini closely. If the bread browns too quickly while the cheese isn't melted, lower the heat slightly. You can also tent the panini with foil to retain heat while cooking longer.

→ Can I make this with leftover cooked chicken?

Yes, leftover rotisserie or grilled chicken works perfectly. Skip the grilling step and simply slice the cooked chicken thinly. Warm it briefly if desired, then assemble and press as directed.