Preheat oven to 350ºF/175ºC. Trim ends from zucchini and slice into long noodles (zoodles) using vegetable peeler or mandolin. Cut top off peppers and scoop out any of the seeds/core. Remove sausage from casings and place in a frying pan and cook on medium heat, breaking the meat apart with a spoon as it cooks. Once cooked, add the Pomodoro sauce to meat, stir well until fully mixed and sauce is heated through, then remove from the heat and bring to prep area (vegetarian option: add sauce and cooked orzo to a pan, heat through, then remove from heat). In a small bowl, mix together the ricotta, parmesan, egg, nutmeg and salt and pepper to taste. Fill the pepper in layers: start with a small layer of the meat sauce, layer of zoodles (1-2 thick, cut zoodle to size to fit), small layer ricotta mix, layer zoodles, repeat until pepper is filled. Fill all peppers the same way. Sprinkle top of peppers with mozzarella cheese. Place in oven for 40-45 minutes, or until heated all the way through and cheese has browned. Serve.