In a large skillet,saute the onion,pepper,garlic in the olive oil until softened slightly.Brown the onion and garlic a little first,then add the yellow pepper.
While this is cooking,get your pasta rolling in salted boiling water for just about 4-5 minutes.You want it to a little under cooked as it will finish cooking in the oven.You also will need a 3 quart casserole dish.
Remove the vegetables to the side using a slotted spoon leaving the oil,add the sausage meat and brown it,breaking it up with your spoon as you go,remove it when it's done using the slotted spoon and leaving the drippings and oil to brown the chopped meat next.After the meats and the vegetables are done,get rid of the oil,deglaze the pan using a little cold water,scraping up all of the goodies from the pan,add it to the vegetables into the casserole dish.
Now,add the sauce to the meat mixture and the fennel seed.Next you add the barely cooked pasta to the mixture tossing it well to coat everything. Keep in mind this can be done right in the casserole dish!
Next you want to mix together the ricotta,beaten egg,parsley and Romano cheese. put big dollops,about eight in the pasta,spacing around the dish evenly.Spread the grated mozzarella around the top and bake in a preheated 375 oven for 35-40 minutes.
Let the pasta rest for 10 or so minutes to allow it to set before serving.Keep in mind the cooking time also reflects the time it takes to cook the prep ingredients. Enjoy!! :)