Marinade the day before (this is optional, but the trout tastes even better if you do) by whisking together the soy sauce, pure maple syrup, crushed garlic and chili flakes in a small bowl. Add the trout filets to a baking dish and pour over the sauce. Turn the fish to coat. Place in the fridge and leave until baking or bake right away if not marinating the trout.
Preheat the oven to 400 degrees.
While the oven is heating, cut the potatoes, toss them in a bowl with the olive oil and sea salt, and place them cut side down on a pan covered in tin foil.
Add the baking dish with the trout to the oven, covered with a lid or tinfoil and the pan of potatoes. I recommend placing the potatoes on a rack at the middle to bottom of the oven and the trout on a rack in the middle.
Bake/Roast for 15 minutes.
Meanwhile, steam the vegetables of choice.
Once the baking time is up, remove the trout and potatoes from the oven and serve, drizzling the sauce from the baking dish over the trout, potatoes, and vegetables!