01 - Preheat a grill pan or skillet over medium-high heat.
02 - Slice chicken breasts horizontally to form thinner cutlets. Drizzle with olive oil and season both sides with salt and black pepper.
03 - Grill chicken cutlets for 4 to 5 minutes per side until thoroughly cooked and golden brown. Remove from heat, let rest for 2 minutes, then slice if desired.
04 - If desired, lightly butter the inside of each roll. Toast the cut sides on the grill pan or skillet until crisp and golden.
05 - Spread a generous layer of basil pesto onto the bottom half of each roll.
06 - Add grilled chicken, top with mozzarella slices, tomato rounds, and baby arugula or spinach.
07 - Cover with the remaining roll halves and serve warm or at room temperature.