Blend coriander, mint, salt, garlic, and chillies into a rough paste in a food processor.
Mix in lime juice, sugar, ginger, and fish sauce until smooth.
Combine the sauce and salmon in a heat-proof bowl and marinate for 20 minutes.
Boil water in the bottom of a steamer.
Place the bowl of salmon in the steamer and steam for 6 to 8 minutes.
Blanch pak choi and rice noodles in boiling salted water for 1 to 2 minutes.
Drain the noodles and vegetables and place them in a serving bowl.
Toss the noodles with garlic, soy sauce, honey, ginger, and chicken stock.
Serve the noodles and greens topped with the steamed salmon.