1 large leek (white and pale green parts only) sliced thin
2-3 large russet potatoes, peeled - 2 inch chop (more potato = thicker soup)
5-6 cups chicken stock (low sodium)
Salt & Pepper to taste
Method
In a large stock pot melt the butter. Once melted, add the fennel, fronds, leeks, salt & pepper. Saute until soft, roughly 10 minutes.
Add the potatoes and the broth (which should cover all the ingredients) and bring to a boil. Reduce heat slightly and allow to simmer for 15-20 minutes, partially covered.
Now it is time to puree the soup. The easiest way to do this is with an immersion hand blender. Just keep at it until it comes to a smooth consistency and most of the chunks of potatoes are gone. I do like when there is one or two small chunks remaining. If you don't have an immersion blender things do get a bit more high-maintenance...you need to puree the liquid in batches in a food processor (or blender). So, pour out a few ladles at a time and puree, being careful with the hot liquid. Pour the pureed soup into a new pot.
Ladle into individual bowls and serve. If you are having company over and you want to be all showy and stuff, you can put a piece of fennel frond in each bowl.
Recipe by FEASTS AND FOTOS at https://www.feastsandfotos.com/2009/01/13/potato-fennel-and-leek-soup/