Steaming and boiling times depend on the robustness of the leaves and how tender or crisp you would like them: red Russian needs 1–2 minutes; curly and cavolo nero 4–8 minutes. Err on the side of undercooking, as overcooking destroys kale’s texture. Alternatively, wilt your kale leaves as follows:
Strip out the stalks and rinse the leaves. Melt some butter in a frying pan and fry a couple of cloves of finely chopped garlic on a low heat for 1–2 minutes, until starting to colour.
Add the kale and cook over a high heat until starting to wilt, about 1–5 minutes, depending on variety. Use tongs to toss the kale around and ensure an even cooking.