Line a large baking tray with a Silpat or parchment paper.
Add all of the ingredients to a food processor except the water and the walnuts.
Process until well combined but leave a little bit of texture.
Add just enough water to bring it all together but not so much that you are unable to shape it. Test with a piece in your hand if you are not sure. You might not need any. it depends on how dry your chickpeas are.
Add the walnuts and pulse until just combined. You want to keep some crunchy texture there.
Shape into patties (or balls if you prefer) and place on your prepared tray.
Brush with oil (optional but gives them a slightly better crust)