Saute Scallions and mushrooms in oil until limp, about 5 minutes. In a blender, combine garlic, chckpeas and chickpea liquid, blend until smooth. Transfer to a large bowl and combine with mushroom mixture. Grind sunflower seeds in a blender or food processor to make a coarse meal, add to chickpea mixture along with curry powder. Mix well. Stir in egg whites or bread crumbs. Mixture will be soft, On a large baking sheet or bread-board, make 8 to 10 beds of sesame seeds for patties. Shape burger mixture into 8 patties and place on seeds. Flip to coat both sides generously. Grill on a well-oiled vegetable grill for 3 to 4 minutes on each side, until brown.