Preheat your oven to 350°F (175°C).
In a large skillet over medium heat, cook the ground beef until browned. Drain excess fat.
Add chopped onion and minced garlic to the skillet, cooking until the onion is translucent.
Stir in the diced tomatoes (with juice), frozen mixed vegetables, Italian seasoning, salt, and pepper. Simmer for about 5 minutes.
Meanwhile, bring a large pot of salted water to a boil. Cook the elbow macaroni according to package instructions until al dente. Drain and set aside.
In a large mixing bowl, combine the cooked beef mixture, macaroni, condensed cream of mushroom soup, and 1 cup of shredded cheddar cheese. Mix well.
Pour the mixture into the greased 9x13-inch baking dish. Spread it evenly.
Top with the remaining cup of shredded cheddar cheese.
Bake in the preheated oven for 30 minutes or until the cheese is melted and bubbly.
Remove from the oven and let it cool for a few minutes before serving.