Turn on the Instant Pot and se to the "saute" setting. When it is hot add sausage and let it sit for one minute, then start breaking it into small pieces or bits. Keep turning and cooking for 2 minutes.
Put the sausage to the side of the pot, add cooking oil and cook onion until fragrant.
Add garlic and leek, then cook for about 15 seconds. Give sausage, onion, garlic, and leek a quick stir and change the instant pot setting to "Warm/Off".
Add chopped tomatoes, tomato paste, chicken broth, dried basil, (optional) dried Italian seasoning, chopped kale and diced carrots into the pot.
Set the instant pot to "Manual" and give it a cooking time of 3 minutes.
When it's done, allow it to release pressure naturally for about 1 minute, then slowly release all remaining pressure.
Add the cannellini beans, salt/pepper to taste and give it a quick stir. Adjust seasoning if needed.