Press [Sauté] mode on the Instant Pot, and use [Adjust] to select “More” mode. When the word “Hot” appears, swirl in oil. Add sausage, and cook with the lid open for 6 minutes or until browned, stirring to crumble. Drain sausage, and set aside.
Add 4 1/2 cups water and broth to cooker, scraping cooker to loosen browned bits.
Sort and wash beans. Add beans, fennel, and oregano to cooker. Close and lock the lid of the Instant Pot. Turn the steam release handle to “Sealing” position. Turn cooker off. Press [Manual]; select “High Pressure,” and use [-] or [+] to choose 29 minutes pressure cooking time. When time is up, turn cooker off. Open the cooker using Natural Pressure Release.
With lid off, press [Sauté], and use [Adjust] to select “More” mode. When mixture comes to a boil, stir in cooked sausage, bell pepper, and tortellini.
When mixture returns to a boil, turn cooker off. Press [Sauté], and use [Adjust] to select “Normal” mode. Simmer 7 minutes or until tortellini is done.
Ladle soup into 12 bowls; top with arugula and pesto. Enjoy!