Brown the beef: Place a large skillet over medium heat. Add the ground beef and cook until browned, breaking it into crumbles. Drain excess grease.
Add tomatoes: Stir in the diced tomatoes (with juice) and simmer for 2 minutes.
Stir in macaroni: Add the uncooked macaroni and 1 cup of milk. Stir well to combine.
Mix in veggies: Add the frozen corn and peas, mixing thoroughly.
Simmer: Reduce heat to low, cover, and cook for 10–12 minutes, stirring occasionally.
Finish with cheese: Stir in the cheese packet and half of the shredded cheddar until melted. Season with salt.
Top and serve: Sprinkle remaining cheddar on top, cover for a minute to melt, and serve hot.
