In non-stick skillet over medium-high heat, brown the onion in 1 tbsp (15 ml) of the oil. Transfer to a large bowl.
In a large pot of boiling water, add the vermicelli. Remove from the heat and let rest for 3 minutes or until tender. Rinse under cold running water and drain. Snip the vermicelli with scissors to shorten.
Add the noodles, carrot, cucumber, cilantro, mirin, soy sauce, rice vinegar and sambal oelek to the onions. Toss to coat.
In the same skillet over high heat, brown the fish in the remaining oil until the desired doneness. Season with salt and pepper.
Place the noodles and vegetables on serving plates. Garnish with the tomatoes and avocado. Top with the seared fish.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.