In a bowl, add the dehydrated nameko mushrooms with 2 cups of water and the mushroom stock. Set aside.
In another bowl, add the chopped veggies, and marinate with the soy sauce, sushi seasoning and sesame oil. Set aside
In a saucepan over medium heat, add the oil and let it heat up
Add the shallots, and stir until fragrant
Add the garlic, dried chilli and black beans. Stir for another minute.
Add the hydrated nameko mushrooms from the water bowl, and keep the water aside. Stir in the mushrooms until dry.
Mix in the mushroom stock water and let the mixture simmer for about 3-4 minutes.
Add the sugar, and chilli oil. Mix until the texture is dry.
Take it off the heat to cool. Once it's cool, it's ready to use for stuffing the baos.