Make bruschetta topping: in a medium sized bowl. Combine the red onions, garlic, tomatoes, ¼ teaspoon salt, ⅛ teaspoon pepper, 1 teaspoon olive oil, oregano, and basil. Set bruschetta to the side. Drain slightly before using.
Grill your chicken: season with salt and pepper and rub with about 1 tsp. of olive oil and grill over low flame until 160 degrees on a meat thermometer. Meat is ready to turn when it no longer sticks to the grill. Do not overcook
Split your rolls in half then stack back together, lay on a sheet pan and toast for 5 min in a 350 degree oven.
To assemble, spread pesto sauce on each half of the roll, then layer with lettuce or arugula, mozzarella, grilled chicken then drizzle with balsamic reduction and top with the bruschetta topping. Season with salt and pepper if desired. Serve immediately.