Cook the green beans in boiling water until tender but still with a bite. Refresh in cold water, drain and chop finely.
Cook the bulgur in boiling water for 1 minute. Remove from the heat, cover and leave to stand.
Grate the courgette and carrot, then peel, core and grate the apple. Wrap in a clean tea towel and squeeze out excess moisture. Combine with the green beans in a mixing bowl.
In a blender or food processor, purée the chickpeas, onion, peanut butter, oil, curry powder and chilli powder until smooth. Season with salt and pepper. Add to the grated vegetables.
Drain the bulgur through a strainer, pressing with the back of a spoon to extract excess liquid. Add to the bowl. Add the breadcrumbs and refrigerate for 1 hour.
With wet hands, shape the mixture into four burgers. Cook under a medium grill for 3 minutes on each side. Serve hot.