Prepare the Green Goddess Dressing: Blend all the dressing ingredients in a small blender or food processor until smooth and creamy. If the dressing is too thick, add a small splash of vinegar or water to thin it out.,Make the Salad: In a large bowl, mash the chickpeas to your desired consistency, leaving some whole for texture. Add the finely chopped cabbage, cucumber, red onion, jalapeño (if using), and mashed avocado. Stir in lemon juice, and season with salt and pepper.,Assemble the Sandwich: Spread hummus on one slice of bread and top with fresh spinach. Add a generous scoop of the chickpea salad mixture and top with mustard or your preferred condiment on the second slice of bread. Close the sandwich.,Serve: Cut the sandwich in half and enjoy!