1 bunch scallions (white and green parts finely chopped)
1 tablespoon tomato paste
1 teaspoon Italian seasoning
One 14 1/2-ounce can diced tomatoes
2 cups shredded Cheddar
Preheat oven to 425F.
Cook noodles to al dente according to package directions. Lightly spray a 2.5-quart casserole dish with cooking spray, drain the noodles and place them in the bottom of the casserole dish and mix the noodles, parmesan cheese, sour cream, and ¼ teaspoon salt together until well combined.
While the noodle is cooking using a large skillet brown the ground beef over medium-high heat until beef is no longer pink inside. Add the chopped pepper and scallions; continue cooking until the onion and pepper is crisp-tender. Scrap out a room in the bottom of the skillet for the tomato paste and cook the paste for about 1 minute. Add the diced tomatoes and then stir in the Italian seasoning and ¼ teaspoon of salt. Cook until mixture is slightly thickened.
Pour the beef mixture over the noodles and top with the shredded cheddar; bake for 15 to 20 minutes, or until cheese is melted and edges are bubbling.