2/3 cup mirin
1/2 cup sake
1/4 cup soy sauce
2/3 cup mayonnaise
2 tablespoons finely grated ginger, with juices
1 tablespoon plus 1 teaspoon wasabi paste
1/4 cup prepared Japanese sesame dressing
1/4 cup prepared ponzu sauce (citrus-soy sauce)
6 cups baby spinach
1 tablespoon mirin
1 tablespoon sake
1 tablespoon soy sauce
3 tablespoons miso
2 1/2 pounds ground chuck
1/3 cup sliced green onion
2 teaspoons finely grated ginger, with juices
2 tablespoons minced garlic
2 teaspoons coarsely ground black pepper
1 teaspoon sea salt
Vegetable oil, for brushing on the grill rack
6 sesame seed buns, split