In a large skillet over medium-high heat, brown the ground beef and diced onions until meat is cooked through and onions are soft. Drain excess grease.

Reduce heat to medium-low. Add minced garlic and cook for 1 minute. Stir in taco seasoning and beef broth. Simmer for 3-5 minutes until the liquid thickens and coats the meat.

Wrap the tortillas in a damp paper towel and microwave for 30-40 seconds until warm and pliable.

Place about 1/3 cup of the beef mixture and 1/2 cup of the mixed cheeses slightly below the center of each warm tortilla.

Fold the bottom over the filling, fold in the sides, and tightly roll it up like a burrito. Secure with a toothpick if necessary.

Heat about 1 inch of oil in a deep skillet to 350°F-375°F. Carefully place the chimichangas seam-side down into the hot oil.

Fry for 1-2 minutes per side until golden brown and crispy. Remove and drain on a wire rack or paper towels.

Top with sour cream, fresh tomatoes, and cilantro. Serve hot.