Heat the oil in a large skillet over medium-high heat. Add the onion and celery and cook until softened, 5 minutes. Add the garlic and cook for 1 minute longer. Remove from the heat and set aside to cool. 

In a large bowl, combine the hearts of palm, artichoke hearts, Old Bay seasoning, cornstarch, nori flakes, and mayo. Add the cooled onion mixture and 1/4 cup of the panko, and mix well. Divide the mixture into 6 to 8 portions and shape into small patties.

Place the remaining 1/2 cup panko in a shallow bowl. Coat the patties with the bread crumbs and refrigerate or freeze for 20 minutes or longer.

Heat a thin layer of oil in a medium skillet over medium-high heat until hot and shimmering. Carefully place the patties in the skillet and cook until golden brown on each side, 3 to 4 minutes per side. Transfer the cooked patties to a plate. Serve hot with lemon wedges.