There are lots of 'Chickpea Tuna' recipes if you use your search engine or read other blogs, some of them using seaweed to enhance a fishy taste and others using a variety of different ingredients. For me I have settled on my favourites and now I tend to stick to this recipe every time I make it.
One tin of chickpeas, drained and rinsed
One small red onion (or white or Spring)
One and a half sticks of celery (there are 3 halves in this photo)
Garlic (1 clove, minced or garlic powder or flakes)