In a small bowl, whisk the oil with the lemon juice, garlic, oregano, basil, salt, and pepper.
¼ cup extra-virgin olive oil, 1 tbsp lemon juice, 2 cloves garlic, 1 tsp dried oregano, 1 tsp dried basil, 1 tsp Kosher salt, ½ tsp black pepper
Pound the butterflied chicken cutlets to ¼-inch thickness. Place them in a large plastic baggie (or a medium bowl) and add the marinade. Massage the marinade into the chicken and chill in the fridge for 20 to 30 minutes, or up to 4 hours.
2 large chicken breasts
Make the Sandwiches
Preheat your outdoor grill to medium-high heat. If desired, place a grill pan over the direct heat (or a large cast-iron skillet) for toasting the buns. See NOTES.
Butter the buns and place them on the grill plate or directly on the grates over direct heat. Once golden and toasty, remove from the grill and set aside.
4 ciabatta rolls, 2 tbsp unsalted butter
Meanwhile, remove the chicken from the marinade and place it on the grates over direct heat. Cook until fully cooked and grill marks are visible, about 5 minutes per side.
Move the chicken to the grill pan (or just leave them on the grates) and place the cheese slices over the tops of the cutlets. Cook until mostly melted, 1-2 minutes. Remove from the grill.
4 slices smoked mozzarella
Smear a generous layer of the pesto sauce on each of the bottom buns. Add a layer of arugula and then tomato slices. Season the tomatoes with salt and pepper. Add the grilled chicken with mozzarella. Add another layer of pesto on the cut side of the top bun and add it to the sandwich. Slice in half, if desired, and serve immediately.
1 cup baby arugula, 2 large tomatoes, salt and pepper
Video
Notes
NOTE: Watch the video in the recipe card for visual guidance.
No Griddle for the Grill? No problem! Toast the buttered ciabatta directly on clean grill grates over low/indirect heat for 1 to 2 minutes, or set a cast-iron skillet or rimmed baking sheet right on the grill. To melt the cheese without a flat top, cover the chicken directly on the grates with the grill lid, a metal melting dome, or a tent of aluminum foil to trap the heat and steam.
Make Ahead Tips: The pesto can be made up to 3 days in advance and stored in the fridge with a thin drizzle of olive oil on top to keep it vibrant green. The chicken can marinate in the refrigerator for up to 4 hours. The ciabatta rolls can be made 24 hours in advance, and the mozzarella needs to rest in the fridge for 1 week before slicing.
Cheese Prep: For clean, even slices, pop your smoked mozzarella in the freezer for 15 minutes before running it through a deli slicer or slicing with a sharp knife.
Internal Temp: Always cook the chicken cutlets until an instant-read thermometer inserted into the thickest part registers 165°F (74°C).