This is undoubtedly the most natural way to feed your pet rabbit
I feed my rabbit chunks
of carrot, broccoli, herbs like
mint, parsley etc, Banana, cauliflower, cabbage / broccoli / Cauliflower stalks, plus a commercially available food and fresh water and hay daily. The food and vegetables can be fed frequently once your rabbit is used to them.
There are also various treats marketed for rabbits ranging from milk-based yoghurt drops to sticks of cereals / grains.