Preheat oven to 375 degrees. Mix mirin, soy sauce, sake, sugar and white miso in a bowl till it forms a paste.
Coat frozen salmon fillets with miso paste.
Wash and dry produce and cut the ends off asparagus. Cut potatoes in half.
In a mixing bowl, season veggies with a drizzle of olive oil, salt, and pepper. Place on a baking sheet. Bake at 375 degrees for 8 – 10 minutes.
Season marinated salmon fillets with salt and pepper, and place on top of veggies. Bake for 25 – 30 minutes.