Optional toppings, like sliced olives, bell peppers, mushrooms, Parmesan cheese, etc.
Preheat oven to 350° and spray an 9x12 casserole dish with non-stick cooking spray and set aside. I
In a large pot of boiling, salted water, cook your pasta until al dente. Drain and set aside.
In a large skillet, cook beef and onion over medium heat until meat is no longer pink; drain off any excess grease. Stir in marinara sauce and pasta.
While the pasta is cooking, to a large skillet over medium heat, add the ground sirloin and chopped onion and season with Italian seasoning, Montreal steak seasoning, and salt and pepper. Cook until no longer pink.
Stir in the spaghetti sauce to the cooked beef. Pour in the cooked and drained pasta and stir to evenly distribute.
Pour the mixture into the prepared baking dish, sprinkle with cheese, and arrange pepperoni (& any other toppings) on top.
Bake, uncovered, 25-30 minutes or until cheese is melted. Optional: Garnish with parsley, basil or Italian seasoning if desired.
Freezing Instructions: Prepare as directed but do not bake. Cover and freeze up to 3 months. Once you're ready to make it, move the casserole from the freezer to the fridge overnight to partially thaw. Remove from refrigerator 30 minutes before baking. Preheat oven to 350° and bake as directed, increasing the cook time to 35-40 minutes or until heated through.
If you don't have enough Mozzarella, you can combine with jack or cheddar cheeses.
Instead of marinara sauce, spaghetti sauce or pizza sauce can be used.