Preheat oven to 375°. Slice stem off onions and peel off outer papery layer as well as the top layer of skin to reveal flesh. Using a spoon, gently scoop out the center of flesh leaving a few of the outer layers. Reserve some of the scooped out onion. Lightly rub each onion with olive oil and season with salt and pepper. Place onions in a 9” pie dish or small baking dish. Cover with foil and bake for 30 minutes.

Meanwhile, melt 2 tablespoons butter in a large skillet over medium heat. Chop 1/2 cup onion from reserve and add to skillet. Cook until just tender, about 5 minutes. Add garlic and cook about 45 seconds until fragrant. Stir in 2/3 chicken broth and stuffing. Stir until all liquid is absorbed into stuffing. Remove from heat and stir in oregano, parsley and season with salt and pepper.

Once onions have baked for 30 minutes, remove from oven and divide stuffing mixture into each onion. Cube remaining butter and place in the bottom of baking dish along with remaining chicken broth. Cover with foil and bake for another 40 minutes, basting occasionally until onions are tender.

Uncover, sprinkle with mozzarella and cook 10 minutes until cheese has melted.