In food processor, place frozen teriyaki vegetables and onion; process with on-and-off motions until finely chopped. Place in large bowl. Stir in ground pork, bread crumbs and ginger until well blended. Shape mixture into 4 patties, about 5 inches in diameter and 1/2 inch thick.
Spray 12-inch skillet with cooking spray; heat over medium heat. Add patties; cover and cook 10 to 12 minutes, turning once, until browned and meat thermometer inserted in center of patties reads 160°F.
Meanwhile, in small bowl, mix mayonnaise, teriyaki sauce and yogurt with wire whisk until well blended.
Spread mayonnaise mixture evenly on top and bottom halves of toasted buns. Top bottom halves with patties and cucumber slices. Cover with top halves of buns.