Add sausage and onions to large pot (we used a 5-quart pot) and cook over medium-high heat until sausage is browned and onions are translucent
Add garlic and cook for about 30 - 45 seconds
Add chicken stock, uncooked pasta, diced tomatoes, and milk. Bring to a boil, cover the pot, and then reduce heat to low. Let it simmer for about 15 minutes. Pasta should be cooked in that time.
Turn off the heat and then add half of the cheese and stir into pasta.
Serve in bowls and top with more cheese. Enjoy!
Recipe by Family, Love, and Other Stuff at https://familyloveandotherstuff.com/cheesy-one-pot-sausage-pasta-recipe/