Turn IP to saute. Once hot add oil to the pot and place the ground beef, Worcestershire sauce, and onion in the pot. Brown the meat, breaking it into small pieces as it cooks. Remove excess grease. *See notes.
Add the garlic and cook for 1 more minute.
Stir in the flour, cream of mushroom soup, beef broth, water (if using-see notes), and noodles and stir to combine.
Secure the IP lid and turn valve to the sealing position. Cook on Manual Setting or High Pressure Setting for 2 minutes.
When pressure cooking has completed, do a quick release. (I like to wear a hot pad glove when doing this in case liquid sprays from the knob. If there’s liquid spraying you can also turn the knob only half way so only a small amount of steam is being released if you prefer).
Carefully remove the IP lid, stir the mixture, and then let cool of a minute before adding the sour cream.
Stir in the sour cream, parsley and salt and pepper (can use more or less to taste). Serve!