Preheat the oven to 350 degrees and grease a 9x13" baking dish. Cook pasta al dente according to package directions, then drain and transfer to a large bowl tossed with a tablespoon of olive oil. Heat remaining 3 tablespoons of oil in a large skillet over medium-high heat and saute the beef, onions, peppers (reserving 1/4 cup for later), and garlic until the beef is browned. Add sauce and seasonings (you may not need the whole jar of sauce depending on how "saucy" you want the casserole to be). Transfer the mixture to the bowl with the noodles, and mix to combine, then pour into the prepared baking dish and sprinkle reserved diced peppers and cheese on top. Cover with foil and bake for 25 minutes, then remove the foil and cook for an additional 10 minutes or until the cheese is bubbly and lightly browned. Serve with crusty bread or a side salad.