Leek and Potato Soup, with Kale and a Turnip

My mom always made leek and potato soup and served it with salad and buttery toasted pita. It's such a great dinner for a cold day. I wanted to make the usual soup, but I also picked up a turnip and a bunch of kale to change it up a little. I ended up making way more soup than necessary, so I'll be eating it for days. All of the ingredients cost $10. It's really tasty, and the kale gives it a nice green color (and some extra healthiness). Serve it with some pita toasted with butter and a salad.

Ingredients:
5 medium-sized potatoes (any kind you want), peeled and chopped into 1" cubes
3 large leeks, rinsed and thinly sliced
1 turnip, peeled and cut into 1" cubes
2 tbsp butter
1 bunch kale, rinsed and ripped into pieces

salt and pepper
water
1 1/2 cups whole milk
1/4 tsp cayenne pepper

Directions:

Melt the butter in a large, heavy bottomed pot over medium-high heat. Add the leeks and a big pinch of salt and saute until soft but not brown, 5-10 minutes.

Add the potatoes and turnip and 10 cups of water with 1-2 tbsp of salt. Bring to a boil. Once boiling, stir and reduce to a simmer.

Once the potatoes are tender (about 15 minutes) add the kale and let it cook for about five minutes.

The kale should be wilted and tender. You can then either transfer it in batches to a food processor, or blend it using an immersion blender. Blend until very smooth. (If you don't want any dots of kale, you can pour through a fine mesh sieve.)

Add milk and season to taste with salt, pepper, and cayenne. You will need a lot of salt - just be warned.

I like to serve it with a thin slice of butter on top.