Dump all ingredients except for plum tomatoes, scallions and sour cream in Instant Pot. Set to manual and pressure cook on high for 4 minutes. Instant Pot will take about 10 minutes to pre-heat and then the 4 minutes to cook. When complete, press cancel and do a quick release of the steam, waiting until the pressure gauge drops back down and the lid is safe to open. Remove lid, stir contents well and divide among 6 bowls. Top with plum tomatoes, scallions and sour cream (I also sometimes add cheese, lettuce, more cilantro, avocado and whatever other veggies I have on hand). Serve and enjoy!