1. Rinse and drain beans; trim and discard stem ends. In each of two 12- by 17-inch baking pans, mix half the beans with half the olive oil; spread level.
2. Bake in a 450º regular or convection oven until beans are slightly browned and tender when pierced, 15 to 25 minutes; switch pan positions halfway through baking.
3. Stir half the sesame seeds and half the sesame oil into beans in each pan; continue baking until seeds are golden, about 5 minutes longer. Pour into a bowl, add soy sauce to taste, and mix well.