In a large skillet over medium heat, add 1 pound lean ground beef and 1 cup diced onion. Cook and crumble the beef until brown and no pink remains. Drain excess grease if needed.
To the skillet, add 1 (1-ounce) packet taco seasoning, 1 (10-ounce) can rotel, 1 (10-ounce) can enchilada sauce, and 1 cup beef broth. Stir to combine and bring to a boil. Once boiling, stir in 2 cups elbow macaroni. Turn the heat to medium-low and cover with a lid. Cook for 10-12 minutes, stirring halfway through.
Once the pasta is cooked, stir in 1 cup whole milk and 2 cups shredded cheddar cheese. Garnish with green onion and serve.
Notes
Store leftovers in an airtight container in the fridge for up to 5 days. Reheat in the microwave in 30-second increments until heated through.