Cut the beef into pieces and liberally season all sides with salt, pepper, garlic powder and a drizzle of olive oil.
Set your Instant Pot to the sauté setting and heat a drizzle of oil. Sear the beef on all sides, about 3-4 minutes per side or until browned. Remove the beef and place it on a plate or cutting board.
In the same pot, add sliced onions and cook until fragrant, about 3 minutes. Then, add tomatoes and minced garlic and sauté for another 2 minutes, scraping the bottom of the pot to pick up the browned bits, thats flavor.
Add in onion powder, garlic powder, chili powder, cumin, smoked paprika Mediterranean seasoning blend and allow the seasonings to blend for about 1 minute before adding in the tomato paste and harissa paste. Allow that to caramelize for 2 minutes then carefully pour in the water or broth. Mix to combine.
Return the beef and juices to the pot. Add in salt and pepper to taste. (If you're using beef broth you can skip this step). Add a cap of vinegar and mix until combined.
Using the pressure cook setting cook on high for 45 minutes. After cooking, allow the pressure to naturally release for 20 minutes before manually releasing the remaining pressure. Remove the beef from the pot and shred it.
Optional - Turn the Instant Pot back to the sauté setting and bring the sauce to a boil. Let it simmer for 25 minutes, or until the sauce thickens. Be sure to skim off any fat that rises to the top. Once thickened, pour some of the sauce over the shredded beef.
Enjoy with rice, Cava bowls, gyros, or salads!