Preheat oven to 375 degrees.
Place cauliflower in a large mixing bowl. Drizzle with the olive oil, sprinkle with salt; toss gently until evenly coated.
Lay cauliflower pieces out on a baking sheet.
Bake, mixing with a wooden spatula once, until golden brown and tender, about 25 minutes.
Remove from the oven anŠ² let cool.
Meanwhile, cook the Somen noodles.
Bring a medium saucepan to a boil. Cook the noodles according to the instruction on the package.
Drain and transfer to a large bowl mix with the roasted cauliflower.
In a small bowl whisk all the ingredients for the dressing.
Pour the desired amount of dressing over the noddles and mix with tongs.
Divide noodles among 3 bowls and sprinkle with the toppings. Season with Sriracha sauce to taste.