Best Potato and Leek Soup!

It seems lately that all I want to make is soup.  I finally made one worthy of writing about.   I started preparing for this soup a day ahead of time.  I prepped the leeks and fennel, stored them in Tupperware and made the stock.  For the stock I used the fennel greens as well as the bottom and outer most layer of the bulb.  I also used the tender interior portion of the leeks that can be uncovered when the top, dark half of the foliage is removed and discarded.  The stock had 6 cloves of garlic that were going dry/soft, 1 yellow onion cut in half, some kale stems, one large carrot, handful of parsley stems, 4 deseeded apple cores, bay leaf, salt and a turkey leg- covered in water, brought to a boil and then allowed to simmer for over two hours.  The flavor of this broth seemed perfect for the soup I wanted to make.

For the soup:

You'll need...

4 tablespoons butter
3 med. leeks (clean, remove dark foliage, cut in have lengthwise and slice about 1/4 in thick. Soak sliced leeks in a bowl of cold water washing away any grit or dirt. Rinse, repeat in fresh water- and drain.)
1 small tom med.  fennel bulb with stems ( remove fronds, chop both bulb and stems.)
1 Large yellow onion- chopped
4 small to medium red or golden potatoes (about 1/2 of skin pealed, and sliced very thin) 
5 cups chicken or vegetable broth
salt
fresh ground pepper

Prep fennel, leeks, and onion.  Melt butter in large pot and add the leeks, fennel, and onion with about 1.5 teaspoons salt and some fresh ground pepper.  Cook until soft- but not browned... about 25 minutes, stirring occasionally.   Near the end of their cook time prep the potatoes.
Add a small amount of broth using it to deglaze the bottom of the pot. Add all the potatoes, season them with salt and pepper then and the 5 cups of broth. Bring to a boil, reduce heat and simmer for another 25 minutes.  Blend about 1/2 of the solids in the liquid.   ( You can blend all of the solids if you like,  but I enjoy the mix of creaminess and the separate flavors of the different vegetables.)

I serve with andouille sausage on the side.