Place the chickpeas in a medium-sized mixing bowl. Using a potato masher or the back of a fork, mash half of the chickpeas into a paste, leaving the remaining half of the chickpeas whole.
Add the mayonnaise, Dijon, lemon juice, spices, salt and pepper to the mixing bowl, and stir to combine.
Stir in the pistachios, raisins, green onions, celery and cilantro. The chickpea mixture can be stored in an airtight container in the refrigerator for up to 5 days.
Toast the bread until golden brown.
Top each sandwich with ½ the chickpea mixture, half the tomato slices and a pinch of spinach. Serve immediately.