Preheat oven to 350°F (175°C) and line a baking sheet with parchment paper. Set aside.
Wash the king oyster and pat them dry. Cut each mushroom in half, lengthwise. Next, shred the mushrooms using a fork (see photo). Transfer the shredded mushrooms to the baking sheet and drizzle with the oil. Mix using your hands to coat the mushrooms with the oil and spread them into an even layer. Bake for about 20 minutes.
Remove from heat and transfer the shredded mushrooms to a mixing bowl. Add the soy sauce, coconut sugar, minced shallot and garlic, five spice, and ground chili. Mix to coat the mushrooms with the sauce.
Heat a tablespoon of oil in a large non-stick over medium heat. Once hot, add the shredded mushrooms with the marinade and cook for 5-7 minutes, stirring regularly.
In the meantime, cut the bread in half. Drain the pickled carrots. Arrange about 1/3 cup of pickled carrots on the bottom half of the bread. Top with cucumber slices, fresh cilantro, tofu slices, and the sautéed mushrooms. Optionally, you can drizzle with sriracha or chili sauce for more spiciness. Top with roasted peanuts and close the sandwiches.
Serve immediately! Banh mi will keep in the refrigerator for one day.