How to Make It
Place the potatoes in a large pot with salted water to cover and bring to a boil over high. Reduce heat to medium- low and simmer until the potatoes are tender, about 15 minutes. Remove the potatoes with a slotted spoon and set aside. Return the water to a boil.
Add the kale to the boiling water; cook until tender, 2 to 3 minutes. Remove, rinse under cold water, and squeeze out the excess liquid. Finely chop.
Mash the potatoes, olive oil, salt, and pepper with a potato masher. Stir in the kale.