Preheat your oven to 350°F (175°C).
In a skillet, cook the ground beef and chopped onion until browned. Drain the fat.
Stir in tomato soup, salt, and pepper. Let it simmer for 5 minutes.
Layer the cooked noodles in a baking dish.
Spread the sour cream over the noodles. Don’t worry if it looks uneven—it’ll melt into goodness.
Pour the beef mixture on top. Spread it out gently.
Sprinkle shredded cheddar cheese all over.
Bake uncovered for 20 minutes, or until the cheese is bubbling and slightly golden.