Heat the oven to 150C/fan 130C/gas 2. Cut out the woody stalks from the middle of the kale leaves and discard, then chop the leaves into pieces. Pat the kale completely dry (otherwise it will steam rather than crisp), then put into a large bowl. Drizzle over 1 tbsp of olive oil, then toss to coat the kale thoroughly. (Don’t be tempted to add any more oil, as this will also stop the kale from crisping.)
Line one or two baking sheets with baking paper and spread the kale over in a single layer. Bake for 25-30 minutes (swapping the trays halfway if you’re using 2 and you don’t have a fan oven). Mix the paprika, salt and cumin together, then sprinkle over the kale.