I got my box from a farm CSA and found a lot of leeks in it. It's always a little like Christmas when the box shows up at my door because I never really know what will be in it that I can have some fun with. I decided to make a twist on the more traditional leek-potato soup and substitute cauliflower for the potato. There's a little dijon mustard to give it a bit of a tang and coarsely ground pepper, but the rest is just a great combination of leeks and cauliflower. —TheWimpyVegetarian
Melt the butter in a large saute pan. Add the leeks, salt and thyme and slowly cook over medium heat until the leeks are very soft - about 45 minutes.
Add the chicken broth, cauliflower slices, mustard and pepper. Simmer over medium heat until the cauliflower is very tender, about 20 minutes.
Process until smooth in a food processor and pour the puree into a pot. Reheat and add the milk. Adjust the seasoning and add a squeeze of lemon juice if needed. Serve as is or with minced chives and crouton on top.
To make the croutons, I tore pieces of bread from a fresh loaf, tossed them in enough olive oil and minced garlic to lightly coat them and roasted them in a 400F oven until crispy - about 15 minutes.