Cook the rice in salted water.
Chop the garlic finely and dice the onion, then place both in a bowl, along with the minced meat and rice. Mix everything together.
Add oregano, salt and pepper. Mix again.
Season the inside of each bell pepper with oregano, salt and pepper. Add the stuffing.
Place the peppers in a casserole dish, and sprinkle them with olive oil. Bake for approx. 40 minutes in an oven preheated to 200°C.
Grate the mozzarella a few minutes before the peppers are ready. Sprinkle the cheese over the peppers and place them back in the oven to melt the cheese.
Chop the parsley finely and sprinkle over the peppers prior to serving.