Make the "Mayo": Add the mayo, lemon juice, mustard, and poultry seasoning to a large bowl with black pepper, to taste. Whisk until well-combined.
Mash the Chickpeas: Add the chickpeas to the same bowl, then use a potato masher or a fork to mash them to your liking; I prefer to roughly mash around 75% of them.
Add the Add-Ins: Toss in the celery, onion, parsley, almonds, grapes, and any other optional ingredients. Mix well, then season with additional salt and pepper, if necessary. Serve immediately or refrigerate in a sealed container for up to 7 days.
Sandwiches: To assemble each sandwich, lightly toast 2 slices of bread, and layer each with a piece of lettuce. Place a heaping portion of the chickpea salad onto one slice of bread, then fold the other on top. Serve as desired - lettuce cups, crackers, or veggies on the side are also great ideas!
Meal Prep: I would suggest prepping the Salad ahead of time, but prepping each sandwich the night before to prevent soggy bread. Or, protect each side of the sandwich with a piece of lettuce!
Nut-Free: make the tofu-based version of the mayo, and replace the almonds with sunflower seeds