Chop the spinach very finely (feel free to use a food processor and pulse 3-4 times).
Add the chickpeas, onion, and spinach to a large bowl. In the same food processor add the lime juice, cilantro, sugar, mustard, garlic, chili powder, and olive oil. Process til it comes together into a dressing, about 30-45 seconds.
Pour over the chickpea mixture and stir to combine.
Add salt and pepper to taste.
Let sit for about 10 minutes on the counter or overnight in the fridge to let the flavors marry. Enjoy!