Select the sauté function of the Instant Pot. Add the olive oil and onions. Cook for around 5 minutes, until onions are soft and translucent. add the garlic; cook for 1 minute. Add the tomato paste and cook for 2 more minutes.
Add 1-2 cups of stock. Add the rest of the stock, celery, carrots, zucchini, oregano, basil, salt, diced tomatoes and elbow pasta. Stir to combine.
Put the lid on the Instant Pot, set the valve to 'sealing', and pressure cook on high pressure for 6 minutes.
Stir in the kidney beans and parmesan cheese. Serve with additional parmesan and bread for dipping.