In a small bowl, whisk together white miso, honey, soy sauce, rice vinegar, grated ginger, garlic, hot sauce, 1 tablespoon of vegetable oil, and 1 tablespoon of water until well combined. Reserve half of the sauce in the refrigerator for serving.
Place the chicken thighs on a shallow plate and pour the marinade over them, ensuring each piece is evenly coated. Cover with plastic wrap and refrigerate for 30 minutes to allow the flavors to meld.
Meanwhile, preheat the oven to 205°C (401°F). Line a large baking pan with aluminum foil. Remove the chicken thighs from the refrigerator and arrange them in a single layer on one side of the pan, skin side up.
Then, spread the asparagus on the other side of the pan. Evenly sprinkle with salt and pepper, and drizzle with 1 tablespoon of vegetable oil.
Transfer the baking pan to the oven and bake for 15 minutes or until the chicken is cooked through. Broil the chicken for another 3 to 5 minutes until the top is slightly charred and the asparagus is tender and lightly browned.
Serve immediately with the reserved marinade sauce drizzled on top. Accompany with white rice and asparagus, and sprinkle chopped scallions on top.