In a large skillet or pot, brown the ground beef and chopped onion over medium-high heat. Drain off any excess grease.
Stir in the garlic powder, diced tomatoes (undrained), beef broth, and milk.
Bring the mixture to a boil, then stir in the egg noodles. Reduce heat to low, cover, and simmer for 10-12 minutes, or until the noodles are tender, stirring occasionally.
Remove from heat and stir in the shredded cheddar cheese until melted and combined.
Serve hot.
Notes
This recipe is highly customizable. Feel free to add other vegetables like corn or peas, or adjust the cheese to your preference.