Step 1

Put the potatoes in a medium pot and cover with cold water by at least an inch. Add salt, and bring to a boil. Boil until the potatoes are fork-tender, about 15 to 20 minutes. Drain in a colander and put in a large bowl or the bowl of a stand mixer.

Step 2

Add the butter and the milk to the potatoes and either mix with the paddle attachment or mash by hand with a masher.

Step 3

Boil about 4 cups of water on the stove and get a bowl ready with some ice and cold water and put it next to the stove. Add the chopped kale and boil for 1 minute. Add the chopped onions and boil for 1 more minute. Remove with a slotted spoon and immediately submerge in the ice water.

Step 4

Drain the kale and onions and press down on them to get rid of most of the water. Mix into the mashed potatoes and stir until well combined.

Step 5

Serve with a pat of butter on top while still hot.