Like many of the recipes here, this one is based off ideas from many others I've read and tried before ending up with this version. The kids like it, it's pretty simple, and there is a lot of room for variations on this. You can try some different seasoning blends, replace the beef broth with chicken broth, change our the beef for chicken or even turkey if you wanted (but you may need to add some extra fat to the recipe if you use a really lean meat). Ideally you can do this all in one pan too so clean up is a breeze. Let me know if you try any variations, I'd love to hear how they went.
In a large pot or Dutch Oven if you have one, melt the butter (medium/medium-high heat) and add the ground beef. Cook until browned, breaking it up well as you cook it. Season this with the Salt, Pepper, and Garlic Powder while cooking.
Add the onion to the beef and continue to cook another couple minutes until the onion is softened well.
Dump in the broth and pasta, stir it all together well. Bring it to a simmer, cover it, and let it cook until the pasta is done. Stir this a couple times while cooking, this will take about 12 minutes.
Turn off the heat and pour in the cream, cheddar, and parmesan cheeses, mixing thoroughly. Cover and let sit a minute or two for the cheeses to fully melt and incorporate.