Top with tomato slices and then with grated mozzarella.
Place on ungreased baking sheet and broil until cheese is bubbling and golden brown. 2-3 minutes.
Remove from oven.
Top with arugula and serve immediately.
Recipe can easily be doubled. Feel free to add chopped onions, celery, olives etc...Please keep in mind that the nutritional information provided below is just a rough estimate and variations can occur depending on the specific ingredients used.