Heat a large skillet over medium-high heat. Add ground beef and cook, breaking it up with a spoon, until browned and cooked through, about 5-7 minutes. Drain excess fat if desired.

Sprinkle taco seasoning over the beef and stir to combine. Add diced tomatoes with their juices, tomato sauce, beef broth, and uncooked pasta. Stir well to combine.

Bring mixture to a boil, then reduce heat to medium-low. Cover and simmer for 12-15 minutes, stirring occasionally, until pasta is tender and most liquid is absorbed.

Remove from heat. Stir in 1 1/2 cups of shredded cheddar cheese until melted and creamy. The residual heat will melt the cheese perfectly.

Top with remaining 1/2 cup cheese, green onions, and cilantro. Serve directly from the skillet with lime wedges and sour cream on the side.