1Combine soy sauce, garlic, five spice, sugar, sweet chilli sauce and oil in a screw-top jar. Shake until well combined.
2Place mushrooms in a large ceramic bowl. Pour over three-quarters of the dressing. Stir gently to coat. Cover and stand for 30 minutes to marinate.
3Add prawns, salad greens, capsicum, bean sprouts, carrot, coriander and mint to the marinated mushrooms. Toss gently to combine. Spoon over the remaining dressing. Serve with prawn crackers.