Preheat the oven to 350°F (175°C).
In a large skillet over medium heat, brown the ground beef until no longer pink. Drain excess grease.
Add the chopped onion and minced garlic to the skillet. Cook for another 3-4 minutes until the onion is translucent.
Stir in the uncooked rice, beef broth, diced tomatoes (with juice), frozen mixed vegetables, Worcestershire sauce, salt, and pepper. Mix well.
Bring the mixture to a boil, then reduce the heat and simmer for about 5 minutes, stirring occasionally.
Pour the entire mixture into a greased casserole dish. Spread evenly.
Cover the casserole dish with aluminum foil and bake in the preheated oven for 20 minutes.
After 20 minutes, remove the foil and sprinkle the shredded cheddar cheese on top. Return to the oven and bake uncovered for an additional 10 minutes or until the cheese is bubbly and golden.
Remove from the oven, let cool for a few minutes, then serve.