Prepare all ingredients by chopping the onion, ham, and slicing bell peppers into rings.

Heat a frying pan and sauté the diced ham until slightly crispy.

Add the chopped onion and bell peppers to the pan and stir-fry until softened.

Season the vegetables with ground black pepper and add the cooked rice to the pan.

Add 3 tablespoons of tomato sauce to the rice mixture and stir well.

Fill the bell pepper rings with the fried rice mixture and place them on a baking tray.

Sprinkle shredded mozzarella cheese generously over the rice-filled rings.