Heat the Instant Pot to Sauté, and add the beef. Sprinkle with garlic salt. Brown the beef on all sides (about 7-10 minutes), and transfer it to a plate.
Add the onions, bell peppers, carrots, and celery and sauté for 10 minutes until lightly browned.
Stir in garlic, frozen mixed vegetables, potatoes, tomatoes (including juices), all seasonings, and beef broth. Scrape up any of the browned bits off the bottom of the pot.
Pour in water until it reaches the fill line (about 3-4 cups), and stir well.
Use the Pressure Cook function and cook for 25 minutes. Cover and set the Instant Pot lid to sealing.
Allow the pressure to release naturally for 10 minutes then set the lid to Venting and release the pressure manually.
Stir well, and enjoy!
Notes
*Makes 16 cups of vegetable beef soup.*To replace garlic salt, season the beef with ¼ teaspoon salt and ¼ teaspoon garlic powder.*When searing the beef, you don't need to cook the meat all the way through. You simply want to get a nice brown crust on the beef.*6 small baking or russet potatoes equal about 2 pounds of potatoes.*Use a 12-16 ounce package of frozen mixed veggies (about 4 cups).