Put ground beef or turkey and diced onion in a large, deep skillet and season with salt, garlic powder, and pepper. Cook until browned and drain.
Stir in macaroni noodles, beef stock and milk.
Bring to a slow boil, stirring frequently.
Cover and reduce heat to low. Cook, stirring occassionally, for about 15-20 minutes, until noodles are tender. (I find that the gluten free noodles cook more quickly than regular noodles, so check frequently.)
Remove cover and stir in remaining ingredients, stirring to combine well. If the sauce is too thin for your liking, cook for a few additional minutes.
Enjoy!
Notes
The leftovers of this are fantastic when made with regular pasta, but not so much when you use gluten free noodles. Just something to keep in mind!