Set Instant Pot SAUTE setting.
Add the Olive Oil to the Instant Pot and heat, then add the Ground Beef, Onion, and Garlic. Cook for about 3 minutes, or until the meat is no longer pink.
Add the Oregano, Chili Powder, Salt, Pepper, Worcestershire Sauce, Beef Broth, Milk, and Elbow Macaroni. Stir well, scraping the bottom.
Close the lid, and cook on HIGH PRESSURE for 7 minutes.
When the cooking time is finished, do a QUICK RELEASE, and stir well.
Stir in the Cheddar Cheese and garnish with Parsley.