Turn the pot on to the Sauté setting. Add the ground beef and the onions. Cook, stirring occasionally, until the meat is cooked.
Add the zuchinni, celery, carrot, garlic, oregano and basil. Stir.
Dump the can of diced tomatoes on top and do not stir.
Close the lid and set the steam release knob to the Sealing position.
Cancel the Sauté setting. Press the Pressure Cook/Manual button or dial and then the + or - button or dial to select
7 minutes. Make sure it is set to High pressure. It will take several minutes to come to pressure.
When the cooking cycle is finished, let the pot sit undisturbed for 15 minutes (15 minute natural release). Then carefully, in short bursts at first, release the remaining steam manually, by turning the steam release knob to the Venting position.
Stir the soup well to incorporate the tomato paste.
Serve as desired