Bring a large pot of salted water to a boil. Add spaghetti and cook according to package instructions until al dente.

Drain the pasta in a colander and set aside.

In a skillet, heat olive oil over medium heat. Add chopped onion and minced garlic, sauté until translucent.

Add ground beef to the skillet, cook until browned. Drain excess fat.

Stir in diced tomatoes, tomato paste, Italian seasoning, salt, and pepper. Simmer for 10 minutes.

Add the cooked spaghetti to the meat sauce, tossing to combine. Serve hot, garnished with parmesan cheese and fresh basil.