Preheat oven to 400°F.

Prepare the onions: slice a small portion from each end to make a flat bottom, then slice each onion in half to create free-standing bowls. Gently push from the bottom of the onion to remove all interior layers, leaving 2 outside layers to serve as the completed "onion bowl". Set aside bowls and the interior of one half of an onion, and save the remaining onion in a baggie in the fridge to use for other meals.

Dice the bell pepper and the onion half you saved and set aside.

Cook Italian sausage. Just before it's done (only a little pink meat left), add diced onion and bell pepper. When meat has thoroughly cooked, add cream cheese. Stir constantly until melted. Remove from heat.

Place onion bowls on a cookie sheet. Spoon generous helpings of stuffing into the onions and cover with sliced mozzarella cheese. Bake in oven until cheese is browned and onion is crispy. Remove outer layer of onion that has hardened and serve piping hot!