Cook, stirring to break up, until most of the meat is no longer pink.
Drain the grease, and return the beef to the inner pot.
Add the onion, and cook until softened, about 3-4 minutes.
Stir in the garlic, and cook for 30 seconds, stirring as needed.
Press CANCEL.
Add the beef broth, and scrape up any browned bits from the bottom of the pot.
Sprinkle the oregano, Greek seasoning, and red wine vinegar over the beef.
Close and lock the lid.
Press MANUAL high pressure and adjust the time to 5 minutes.
When the cooking time has ended, let the pressure release naturally for 5 minutes.
Carefully release any remaining pressure by turning the pressure release valve to VENTING.
Give everything a good stir.
Serve in warmed pita bread with your favorite toppings.
Notes
Ground beef - I like to use 85-90% lean ground beef. Ground turkey or ground chicken would also work. If using ground turkey or chicken, you may need to add a tablespoon of olive oil before browning.
White onion - Yellow onion will also work.
Garlic - Feel free to add more garlic if you prefer.
Beef broth - I like to use reduced-sodium beef broth to control the salt levels.
Greek seasoning - I use Cavender's Greek seasoning.