With the rack in the middle position, preheat the oven to 425 °F (230 °C). Line a baking sheet with parchment paper.
On the baking sheet, toss the sweet potatoes with 2 tbsp (30 ml) of the oil. Season with salt and pepper. Bake for about 30 minutes, stirring occasionally, or until the potatoes are tender and beginning to brown. Let cool.
Meanwhile, in a non-stick skillet, brown the fish in the remaining oil (1 tbsp / 15ml) until the desired doneness. Season with salt and pepper. Let cool.
In a small bowl, combine the lemon juice, mirin and sambal oelek.
In a large serving dish, combine the sweet potatoes, cucumbers, arugula, basil and lemon zest. Drizzle with the dressing and toss well. Top with the fish, broken into large pieces.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.