Cook the ground beef in a large skillet until brown (I use my 12" enameled cast iron).
Add the onion and garlic and cook for a few more minutes.
Sprinkle with a little salt and add stock; bring to a boil.
Add the pasta and cook, stirring frequently.
Mix the arrowroot and milk in a measuring cup until smooth.
Pour the milk mix into the pasta mix and stir constantly until a thick sauce forms.
Add the cheddar and stir until melted and smooth.