It's mostly in the title, really.
I start a large pot of water for the penne. I pan fry some Italian sausage in a high temperature oil (I use sunflower oil) until it's brown on the outside then turn it down as I work on the peppers and onions. I fry the peppers and onions in a separate pan until they are translucent. (Don't forget to salt and pepper your peppers and onions as you fry them.) My stove is very hot so I normally add water to help them along then boil it off. I set the peppers and onions aside and slice the sausages into bite size pieces. At this point I add the penne to the water and stir it. I add butter and a high temperature oil to the sausage pan and return the sausage pieces to brown the faces. When the sausage is nicely browned I remove it to a plate with paper towels, pour off as much of the oil as I can, then return the sausage pieces to the pan and pour in tomato sauce (I use a simple tomato basil sauce) and add the peppers and onions. Now I start grating the cheese. I like a low moisture pizza mozzarella (I use Saputo Premium). You'll need enough to cover the top and a couple of handfuls for the sauce. Throw it uncovered into the fridge to keep it cool and dry. Heat your oven up to 350 F. Taste the sauce and adjust the salt and pepper if necessary. When the penne is done drain it, shake as much water out of it as possible, and put it back in the pot. Add the sausage and sauce and stir. Add two large handfuls of mozzarella and stir it in. Dump the pasta and sauce into a 9" x 14" pan. Spread it out in an even layer, add the mozzarella in an even layer across the top. Now grate some nice parmigiana reggiano and sprinkle it across the top of the mozzarella.
Now...put the pan in the top third of the oven and set a timer for 20 minutes. Then the timer goes off turn it 180 degrees and set a timer for another 15 minutes. Then the timer goes off check it, turn it one more time, and leave it for 5 minutes. At this point you're just looking for a nice, crispy cheese crust on top.
Everything but the cheese is cooked when you put it in the oven. You can eat it after about 5 minutes if you want melty cheese. I like my cheese brown and crunchy so the longer cooking time gets that done.
I hope you enjoy it as much as we do.