Soak the noodles in warm water according to package directions while you make the rest of the salad.
To make the crispy onions toss the sliced onions in a bowl with the flour.
Heat a thin layer of oil in a skillet and when it’s hot add in the onions. Cook until brown and crisp. Transfer to paper towel to drain and sprinkle with salt.
To make the dressing whisk together the fish sauce, rice vinegar, sugar, water, chili garlic paste and a pinch of salt.
To make the salad toss together the noodles, salmon, avocado, cilantro, carrot & cucumber.
Toss with the dressing. Top with the onions.
Garnish with peanuts, fresh lime, sriracha.