Soak the dried porcini mushrooms in boiling water for about 15 or more. It can also be prepared the day before. The longer you soak, the more flavor and aroma you get.
Close to using in the recipe (after at least 15 minutes of soaking) - add the soy, sesame oil, lemon juice, Korean chili pepper powder, salt, and pepper to the porcini stock and mix.
Cook the sweet potato noodles in water according to the manufacturer's instructions. When ready, rinse with cold water to stop cooking and remove the starch. It is best to cut the noodles with scissors as they are really long.
Boil water either in a pot or in a kettle and brew the broccoli for 10 minutes. Then rinse with cold water and strain.
Do the same with spinach. Soak it in boiling water for about 30 seconds and transfer it to a colander under cold water or a bowl of ice water. Strain well and squeeze the spinach well from the water with both hands until you form a spinach ball. Cut it into bite-sized pieces and set aside.
Heat 2-3 tablespoons oil in a large frying pan or in a wok and sweat for about 7 minutes over medium heat the ginger, portobello mushrooms and if you want to add tofu, this is the time. Cook until the mushrooms or tofu are golden.
Add the noodles, and the mushroom stock to the pan, and mix. Let the sauce simmer for about 5 minutes. Then add the broccoli, and the cabbage is baked. Continue to cook until there is almost all liquid has reduced.