Set Instant Pot to saute mode. Once hot, add a little bit of oil and add onions. Stir for 1-2 minutes, until slightly translucent.
Add ground beef. Break up and cook through, about 5 minutes. Drain excess grease.
Add remaining soup ingredients to the pot. Stir well.
Set the Instant Pot to manual, high pressure, 15 minutes. Once cook cycle is over, release remaining pressure by turning the valve on the lid.
Once pressure is released from cooker, stir soup well. Serve topped with cornbread, tortilla chips, cheddar cheese, sour cream, and/or diced red onion.
Notes
Don't drain any of your canned ingredients - all of those flavors blend together beautifully in the final soup!
Prep your toppings while pressure cooker cycle is running. You can cook cornbread, dice onion, shred cheese, etc.
This soup makes a great freezer meal! You can either freeze before cooking (cook ground beef and add all ingredients, minus water, to a freezer container) or cook and freeze in smaller servings.
Store leftovers in the fridge for 3-4 days in an airtight container.