Preheat the oven to 350°F (175°C).
In a large skillet over medium heat, cook the ground beef until it’s browned. Drain any excess fat.
Add the chopped onion and minced garlic to the skillet. Sauté until the onion is translucent, about 3-4 minutes.
Stir in the tomato sauce, diced tomatoes, oregano, basil, salt, and pepper. Let it simmer for about 5 minutes.
In a large bowl, combine the cooked elbow macaroni, the meat sauce mixture, shredded cheddar cheese, and frozen mixed vegetables. Stir until evenly mixed.
Transfer the mixture to a greased casserole dish and spread it evenly.
Top with additional cheddar cheese if desired.
Bake in the preheated oven for 30 minutes or until the cheese is bubbly and golden.
Remove from the oven and let it rest for 5 minutes before serving.