Add the bouillon cubes to 4 cups of boiling water. Set aside to dissolve. Use a fork to stir/smash the cubes a couple of times to make sure they're fully dissolved.
Place a large pot or Dutch oven over medium heat. Melt the butter and then add the onion. Cook for 2 minutes until the onions are softened.
Add the ground beef, bacon bits, dry ground mustard, onion powder, salt, and pepper. Use a spoon to break up the beef and stir everything together. Cook for 6-8 minutes until the beef is cooked through and no longer pink.
Add the chicken bouillon mixture to the pot along with the uncooked pasta. Stir everything together, cover the pot, and cook for 20-25 minutes until the pasta is cooked al dente. Stirring occasionally. (see note.)
Uncover the pot and add the sour cream and shredded cheeses. Stir until the cheese is melted and a creamy sauce has formed.
Serve warm with extra shredded cheese on top if desired.
Notes
You can substitute the bouillon and 4 cups water for 4 cups of chicken broth if preferred.
For the bacon, you can use store-bought bacon bits or cooked and crumble your own bacon. (Sometimes I add more bacon if we're in the mood.) This ingredient can be committed if needed.
You can use 3 cups of shredded cheese in any variety you like. Other cheeses that work great for this recipe are pepper jack, Monterey Jack, and even a little Parmesan.
If the pasta isn't cooked enough after 25 minutes, add another 1/4 cup of water or chicken broth, cover, and cook for a few more minutes.