Wash and dry the bell peppers. Cut the pepper in half from top to bottom. Remove the membrane and the seeds. Set aside.
Preheat the oven to 350 degrees F. Cook the orzo using the instructions on the box. Once cooked drain and set aside.
In a skillet add the Italian sausage, chopped onion, and minced garlic. Cook until the sausage is brown and the onions and garlic are soft. Mix in the spaghetti sauce. Add the Italian seasoning and stir until blended.
Stir in the orzo until well mixed. Add about half of the mozzarella and mix in.
Place the bell peppers into a 9 by 13-inch pan. Spoon the Italian sausage mixture, divide between the 8 halves. Cover with aluminum foil and place in the preheated oven.
Bake for 45 to 55 minutes. Testing the peppers for softness. Remove the peppers from the oven and remove the aluminum foil. Top the peppers with the remaining mozzarella cheese and place back in the oven.
Continue to bake for 10 to 15 minutes or until the cheese starts to melt and the peppers are tender.