Place all of the ingredients for the tuna salad (chickpeas through lemon juice) in a food processor. Pulse 15-25 times, not more than 20 seconds, until well-incorporated and combined but still chunky. Season to taste, adding salt as needed.
Step 2
Spread the tuna salad onto four slices of bread bread and top each optional sandwich toppings if desired. Top each with another slice of bread and enjoy.