Preheat the oven to 190°C, fan 170°C, gas 5. Put the kale in a large bowl and mix in the olive oil, salt and sesame seeds.
Spread out on a large baking tray then sprinkle over 2 teaspoons of the sugar. Bake for 7 minutes, then remove from the oven and give it a toss.
Sprinkle over the remaining sugar and cook for a further 7 minutes, until crispy. Mix well again before serving.