Broil the onion, ginger, carrots, daikon, cabbage, and shiitake stems on high for 7 to 8 minutes until charred, or char them with a butane torch.
Toast the dried spices in a dry pan over medium-high heat for 3 to 4 minutes until fragrant, then add them to a spice bag.
Bring 6 quarts of water to a boil. Add the roasted aromatics and the spice bag, then simmer gently for 2 hours. Remove and discard the onion, ginger, and spice bag. Simmer another 4 to 5 hours.
Remove the vegetables and strain the broth. Season with Dear Mam vegetarian fish sauce, MSG, and salt to taste. Add fried tofu puffs and keep warm.
Slice the shiitake caps, trim the king oyster mushrooms, then cut off the seafood mushroom roots and halve them. Sauté the shiitake and king oyster over medium-high heat for 2 to 3 minutes, add the seafood mushrooms, and cook 1 to 2 minutes more. Once browned, add oil and season with salt.
Thinly slice white onion and soak in cold water, then drain. Slice jalapeno, cut lime wedges, rinse bean sprouts, and chop green onion and cilantro.
Blanch the rice noodles for a few seconds until just chewy. Add to a bowl with bean sprouts, green onion, and cilantro. Top with mushrooms, ladle in broth and tofu puffs, and finish with white onion, jalapeño, lime, and black pepper. Enjoy!
