Heat your oven to 200°C/Fan 180°C/Gas 6.
Zest and juice the lemon. Peel and grate or crush 1 garlic clove. Whisk together in a small bowl. Finely chop the rosemary leaves and add those too. Season.
Pop the chicken in a small baking dish. Pour over the lemon, garlic and rosemary marinade. Add 100ml cold water. Cover with foil. Slide into the oven and bake for 30 mins. The chicken should be white and the juices run clear when pierced with a skewer.
Meanwhile, tear the kale leaves from the tough stalks. Peel and grate or crush the remaining garlic clove. Whisk the garlic clove with 1 tsp oil, 1 tsp fennel seeds and some seasoning.
Pop the kale leaves into a bowl and pour over the garlic oil. Massage this into the kale leaves. Spread out on a lined baking tray with 2 tsp of the pumpkin seeds. Slide into the oven for 4-5 mins. The kale should be crisp and slightly golden after this time. If not, keep cooking till crisp (keep an eye on the seeds).
Drain and rinse the butter beans. After the chicken has cooked for 30 mins, remove the foil and tip the beans into the baking dish. Cover again with the foil and cook for a further 5 mins in the oven.
Serve the chicken with the crisped kale, butter beans and the lemony garlic juices.