Heat a large skillet on medium high and add oil. Add ground beef and cook until all pink is gone and beef begins to turn brown. Drain fat if necessary. Add onions and salt and cook stirring frequently until onions begin to turn translucent.
In a small bowl combine chili powder, paprika, onion powder, garlic powder, pepper and all purpose flour. Whisk until well combined.
Once onions are translucent, add garlic and cook for another minute. Sprinkle spice mixture over the ground beef and stir for 1 minute until well mixed and spices are toasted. Stir in tomato paste, then add beef stock and milk. Stir together well and bring to a boil. Cover and reduce heat. Simmer for 10 minutes, checking frequently so it doesn't stick to the bottom of the pot. Add more beef stock or water if necessary.
Add macaroni and stir well. Cover and allow to simmer another 8-10 minutes or until the macaroni has cooked almost completely. This timeframe might vary depending on the brand of your macaroni. It should be about ¾ cooked. Add cheese and stir until melted. Remove from heat and allow to rest 5 minutes or until macaroni is fully cooked.