Soak mushrooms for 40 minutes in hot water. Remove stalks and discard. Cut spring onions into 3.5cm pieces. Seed green capsicum and chili and cut into pieces. Combine marinade ingredients.
Chop spare ribs into large bite-sized pieces and marinate 30 minutes. Deep-fry until brown. Remove from oil. Sauté spring onions and mushrooms in a little oil, add ribs with ½ teaspoon salt, sugar, dark soy sauce and 1/3 cup water and stir-fry. Add capsicum, chili and combined sauce ingredients.
Stir-fry, stirring, until capsicum just starts to lose crispness. Serve on a pre-heated heavy-metal grill pan so meat sizzles. Serve garnished with mint sprigs.
