Set your oven to 425°F (220°C) and prepare a baking dish by lining it with foil for easy cleanup.
In a mixing bowl, combine the orange juice, soy sauce, honey, whole grain mustard, sesame oil, grated ginger, sea salt, and black pepper. Stir until the mixture is smooth and well blended.
Lay the salmon fillets in the prepared baking dish, skin-side down. Pour the citrus glaze over the salmon, ensuring each piece is well coated.
Roast the salmon in the oven for about 10-12 minutes, or until it reaches your desired doneness and easily flakes apart with a fork.
For an extra touch of flavor, switch the oven to broil for the last 2 minutes of cooking, watching closely to avoid burning.
Once done, take the salmon out of the oven, sprinkle with sliced green onions, and serve with fresh orange slices on the side.