In a mixing bowl, combine the rinsed chickpeas and use a fork or potato masher to mash them until they are mostly broken down but still chunky.
Stir in the shredded carrots, fresh dill, celery seeds, dulse seaweed flakes, and a pinch of kosher salt. Mix everything together until well combined.
In a separate small bowl, whisk together the vegan mayo, Dijon mustard, and ume plum vinegar. Fold this dressing into the chickpea mixture until everything is evenly coated.
Take two slices of sourdough bread and spread a generous amount of the chickpea filling on one slice. Top it with one or two slices of vegan cheese, depending on your preference. Place another slice of bread on top to complete the sandwich.
In a skillet over medium heat, melt a little vegan butter or drizzle olive oil. Once hot, place the assembled sandwiches in the skillet. Toast for about 3-5 minutes on each side, or until the bread is golden brown and the cheese is melty.
Remove the sandwiches from the skillet and let them cool for a minute before slicing in half. Serve with a side salad or your favorite chips for an extra crunch!
