Combine the bean sprouts, spring onions, sugar snaps, cucumber and tomatoes in a large serving dish, then toss in the herbs.
Heat the oil in a wok over a high heat until the oil starts to shimmer. Add the garlic and ginger and stir-fry for 30 seconds, then add the squid, fish balls and prawns and stir-fry for 2–3 minutes until just cooked.
Add the chilli, sugar, fish sauce and lime leaves. Continue stir-frying for 1 minute, then toss into the salad bowl with the lime juice, sesame oil and soy sauce. Serve with sweet chilli sauce on the side.