Watercress soup

So I've started up with a CSA program again. Sadly, not with Farmer Chad (his pickup window was just too short and inconvenient for me), but with Local Food Stop, picking up at the new Natural Foods Warehouse right by me. I'm so excited about all this!
This CSA allows you to pick from a menu of what you get in your bag and there's no seasonal commitment. This week I got rainbow carrots, watercress, strawberries, apples, kiwi and broccoli. Watercress was a bit of a wild card for me since I don't recall ever using it for anything, but I figured I'd find something creative to do with it. After reading a bit online about the cancer fighting properties of watercress and running across a few recipes I decided to try a watercress soup. You'll need your immersion blender for this one, otherwise you'll have to transfer to a blender in batches, and that's a pain. I can't say enough about how great an immersion blender is. This soup is light and a great starter or a lunchtime accompaniment. OK, after a few tweaks, here's what I got:

Watercress Soup

1 tablespoon olive oil
1 tablespoon butter
3 small yukon gold potatoes- peeled and cubed
1 onion, chopped
2 or 3 small carrots, peeled and sliced
3 cloves of garlic, pressed
salt, pepper, and seasonings
2 1/2 cups chicken stock or vegetable stock
2 1/2 cups milk
2 nice bunches of watercress, rinsed and large stems removed

Directions

Heat the oil and butter in a large saucepan over medium high heat. Add the potato , carrot, garlic and onion, stirring to coat with the oil. Season with salt and pepper to taste. Reduce heat to medium and saute until tender and fragrant. If you have a bit (1/4 cup) while wine, pour it in to deglaze the pan.
Pour in the chicken stock and the milk, bring just to a boil, reduce heat to low and simmer for 10 minutes, or until potatoes are tender. Stir in the watercress and simmer, uncovered, for 4 to 5 minutes, or until watercress is just cooked. Turn off heat and let cool for a few minutes. Using an immersion blender puree until smooth. Season to your desired taste. I threw a little dill in mine. Top each serving with fresh cracked pepper and shaved cheese if desired.