Wash and soak dried mushrooms in hot water for at least an hour. When they are nice and plump, remove stalks. Strain and reserve ½ cup (120ml) soaking liquid.
Heat vegetable oil in a medium sized saucepan. Sauté garlic for 1 minute. Stir in mushrooms then add dark soy sauce.
Pour in soaking liquid and chicken stock. When liquid comes to a boil, cover, reduce heat to low, and allow it to simmer for 45 minutes. Turn off heat when done.
In a large fry pan, cook bacon until crispy. Remove and reserve 6 tablespoons bacon fat. Cut bacon into thin strips.
Place 1½ tablespoons bacon fat in each of 4 separate bowls. Add 1 tablespoon dark soy sauce and 1 tablespoon regular soy sauce to each bowl.
Bring two large pots of water to boil. Scald choy sum for 1 minute in one pot. Remove and set aside.
Add a bundle of wonton noodles into the water and boil for 2 to 3 minutes or per packaging instructions in the same pot. Scoop up noodles with a metal strainer and rinse under running water in the sink. Then dip noodles back in the other pot of boiling water to reheat it.
Transfer noodles to bowl with soy sauce mixture. Toss noodles to coat with sauce.
Top with cooked choy sum, bacon, and braised mushrooms. Also drizzle 1 to 2 tablespoons of braised mushroom liquid over the noodles. Repeat with remaining noodles.
Serve immediately with boiled or deep fried wontons and pickled green chilies on the side.