Preheat a frying pan then pour the oil in. Fry the ham for 3 minutes. Optionally, use any meat of your choice instead of ham. Put aside.
Set the bell pepper on the base of a microwave-safe bowl. Layer with the onion, ham and finally, tomato paste.
Top with mozzarella.
Microwave for 3 minutes and let the cheese melt. As an alternative, bake for 10 minutes in the oven preheated at 370°F. Remember to use an oven-safe pan for this.