Simmer potatoes in water in a large pot for 15–20 minutes, or until tender when pierced; drain. Return pot to medium-high heat.

Melt butter, then stir in the kale, salt, and pepper. Cook until kale is wilted, 2–3 minutes.

Off heat, add drained potatoes, cheese, and milk; crush with a potato masher until combined but still lumpy. Season with salt and pepper to taste.

Stir the kale into the melted butter with some salt and pepper. Salt draws out moisture, quickly wilting the leaves.	If the crushed potatoes are too dry, add a little more milk. But don’t overmix—that makes the mixture gummy.