Set pressure cooker to saute and add ground beef and diced onion. Cook until meat is no longer pink. Then drain grease and put pot back.
Add garlic salt and stir. In a separate bowl whisk together your can of cream of mushroom soup, worcestershire sauce, and broth until smooth.
Sprinkle in quartered mushrooms, then pour your bag of uncooked egg noodles on top of your mushrooms. Pour your broth mixture over the top of them.
Do not stir mixture. Close lid and steam valve.
Set to high pressure for 2 minutes, then do a quick release. (3 minutes if you like your noodles on the softer side)
Stir in 1/2 - 3/4 c. of sour cream, or serve as is with a dollop of sour cream on top. Or omit the sour cream entirely, totally up to you.
If adding fried onions transfer the casserole mixture from the pot into a 9x9 oven safe dish and sprinkle onions over the top. Can add green onions too.
Using an oven: put under broiler for 3-4 minutes or until onions are light brown, or close air crisp lid on Ninja Foodi and cook at 400 degrees for about 4-6 minutes or until they're as brown as you'd like. Serve with or without sour cream dollop on top.