Turn on the Saute function. Once the screen reads HOT, add Ground beef.
As the meat starts to brown. Use a wooden spatula to chop into crumbles.
Add Dry Mustard, salt, pepper, and onion. Cook until beef is no longer pink and onion is translucent.
Turn off Saute function. Now stir in cheddar soup and milk. Stir very well.
Add 2 cups of water and stir in Macaroni. Mix thoroughly.
Secure lid. Use the manual pressure cook function and set timer for 5 minutes. Set release value to seal.
When cook time is complete use a quick release. Remove lid.
Stir in shredded cheese until melted.
Sprinkle in desired amounts of bacon pieces and serve.