Drain the cooked chickpeas, tip in to a mixing bowl and roughly mash half. Add the garlic, cayenne pepper, spring onions, kale, lime juice, olive oil and pepper.
Slice the avocado in half, remove the pit and scoop out the insides. Cut the avocado in to cubes and add half to the chickpeas. Roughly mash and tip in the remaining avocado cube and stir.
Spoon the mixture in to the avocado skins and sprinkle chopped walnuts on top.