Creamy Cannellini Soup

Turn on a multi-functional pressure cooker (such as Instant Pot(R)) and select Saute function. Once hot, add butter, followed by sausage and fennel. Stir and break up sausage. Cook, stirring, until sausage is browned, about 5 minutes. Pour in 1 cup chicken broth slowly, scraping up any browned bits from the bottom of the pot. Pour in 2 cans of drained cannellini beans. Cancel Saute mode.

Close and lock the lid. Select high pressure according to manufacturer's instructions; set timer for 5 minutes. Allow 10 to 15 minutes for pressure to build.

Meanwhile, combine remaining 2 cups chicken broth and 2 cans of beans in a blender; blend on high until smooth.

Release pressure using the natural-release method according to manufacturer's instructions for 5 minutes. Release remaining pressure using the quick-release method according to manufacturer's instructions, about 5 minutes. Unlock and remove the lid. Add pureed beans, thyme, and truffle salt to soup; mix to combine.

Ladle soup into bowls and serve with a drizzle of olive oil.