You can use either dried or tinned pulses: the recipe will still work but the result will be different. Starting with dried pulses and soaking them overnight will bring about the ‘best’ results (the creamier hummus, for example, as you can use the cooking water when blitzing together the chickpeas), but starting with ready-cooked chickpeas will always, of course, have the advantage of almost-instant readiness. When it comes to fava beans, though, we often prefer using already cooked tinned beans rather than dried ones. For one thing they are easier to get hold of, but the dried ones can also cook unevenly and require peeling.