Lay sliced tomatoes in a 9×13 baking dish, overlapping a few if needed. Sprinkle tomatoes with salt and pepper. In a bowl, mix panko, cheese, garlic and parsley with a spoon until combined. Evenly sprinkle panko mix over top of tomatoes. Broil for 2-3 minutes, or just until cheese and crumbs are golden. Watch carefully as the break crumbs can burn quickly! Serve as a summer side dish, a salad starter, or a snack!