Begin by trimming, slicing and rinsing the white part of your leeks (see notes*)
Wash, peel, and dice the potatoes into small pieces and chop your onion
Turn on the saute function of your Instant Pot, melt the butter over medium heat. Add the onion. Saute until it becomes soft and translucent.
Add the chopped leeks and continue sautéing for another 3 minutes until everything is soft.
Add the diced potatoes to the mixture. Pour in the chicken broth, mix well, and season with salt and black pepper to taste.
Press cancel to cancel the sauté function. Close and secure the lid. Turn the steam release handle to the Sealing position. Push the Pressure Cooker (Manual Setting) button to high pressure and set the time to 6 minutes using the + or - button.
Once the timer is done, quick release the pressure and open the lid. Use an immersion blender to purée the soup until just smooth. Stir in 1/4 cup of whipping cream. Add ground nutmeg to taste.
And voilà! Your Easy Potato and Leek Soup is ready! Serve it with sliced green onions on top and a generous dollop of whipping cream