In a large skillet, bring your beef broth to a simmer over medium heat. Add the large elbow noodles and cook for about 10 minutes, stirring occasionally, until they are tender yet al dente.

Using the same skillet, drain a little of the broth if needed and return it to medium heat. Add the ground beef and chopped sweet onion, cooking until the beef is browned and the onion is translucent.

Reduce the heat to low, and add the cream cheese, shredded cheddar cheese, salt, butter, and heavy cream to the skillet with the browned beef. Stir continuously until the cheeses melt completely.

Once your cheese mixture is smooth, carefully add the drained noodles and diced tomatoes to the skillet. Gently fold everything together until all the noodles are well coated.

Serve the Hamburger Mac and Cheese warm directly from the skillet or transfer to a baking dish for a baked version.