Dice the onion into 1/2-inch pieces, chop the celery into small pieces, peel and cut potatoes into 1-inch chunks, and mince the garlic. Set all prepped ingredients aside. Heat the olive oil in your Instant Pot on the sauté function until shimmering, then add the diced onion and celery. Cook for 4 minutes, stirring occasionally, until the vegetables soften and become fragrant—this helps release their natural sugars and builds a flavorful foundation for the soup.

Add the ground beef to the pot with the softened vegetables, breaking it apart with a wooden spoon as it cooks. After 3-4 minutes, once the beef has started to brown, add the minced garlic and stir constantly for another minute until fragrant. This creates a deeply flavored base—browning the meat develops complex flavors that simple boiling never achieves, and adding garlic at the end of browning prevents it from burning.

Stir the tomato paste directly into the meat and vegetables, coating everything thoroughly for about 1 minute—this toasting step deepens the tomato flavor significantly. Pour in the diced tomatoes with their liquid, followed by the beef broth, and add the potato chunks. Sprinkle the Italian seasoning over top and stir well to combine. I always add the potatoes uncooked at this stage since the Instant Pot pressure cooking will cook them perfectly in just 8 minutes.

Secure the Instant Pot lid and set the valve to the sealing position. Cook on high pressure for 8 minutes. The pressure will build quickly, sealing in the heat that will cook the potatoes tender and allow all the flavors to meld together.

Once the cooking cycle completes, carefully perform a quick pressure release by moving the valve to the venting position. Let the steam escape and wait 30 seconds before opening the lid. Taste the soup and season with salt and pepper to your preference—start with 1/2 teaspoon of salt and 1/4 teaspoon of pepper, then adjust as needed.