Brown the ground beef and onion in the Instant Pot using the Saute function.
Drain grease.
Add broth, potatoes, carrots, celery, and spices.
Place the lid on the Instant Pot and close the valve to seal it.
Set the timer for 5 minutes on Manual, High Pressure.
10 minutes after the timer has passed, release any remaining pressure.
Stir in the milk.
Mix together cornstarch and water.
Add cornstarch slurry to the pot.
Using the Saute function, cook for about 3 more minutes to allow it to thicken.
Stir in the shredded cheese and serve.
Optional: Top with diced dill pickles, tomatoes and/or lettuce for a delicious topping for your Cheeseburger Soup.