Prepare garlic herb sauce and set aside.
Add chickpeas to a mixing bowl and lightly mash with a fork for texture. Then add sunflower seeds, mayo, mustard, maple syrup, red onion, dill, salt, and pepper and mix with a spoon. Taste and adjust seasonings as needed.
Toast bread (if desired) and prepare any other sandwich toppings you desire (tomato, onion, lettuce).
Scoop a healthy amount of filling onto two of the pieces of bread, add desired toppings and sauce, and top with other two slices of bread.
Sunflower-chickpea mixture will keep covered in the fridge for up to a few days, making it great for quick weekday lunches!