To make the mole, heat the broth in the microwave or on the stovetop until hot.
Heat 2 tablespoons oil in a large sauté pan over medium heat. Add the chiles and cook for 10 seconds on each side, or until lightly charred (watch closely as they will char quickly). Transfer the chiles to a blender, add the hot broth, and let the chiles soak while you toast the remaining ingredients.
Add the coriander seeds to the same pan and toast over medium heat for 5 seconds, then transfer to the blender.
Add the sesame seeds, pumpkin seeds, cloves, cinnamon stick, and star anise to the pan and toast over medium heat, stirring continuously, for 1 to 2 minutes, until golden. Transfer to the blender.
Turn the heat down to medium-low. Add 2 tablespoons oil to the pan and, when hot, add the bread pieces and toast on each side for 1 minute, or until golden. Transfer to the blender.
Add the onion and tomato to the pan and cook over medium-low heat, undisturbed, for 4 minutes, then flip and cook for an additional 4 minutes, until beginning to char. Add the garlic cloves and cook for 2 minutes on each side, or until slightly charred. Transfer to the blender. Remove the pan from the heat.
Add the raisins, sugar, chocolate, and salt to the blender and blend on high until smooth, 1 to 2 minutes.
Heat the remaining 2 tablespoons oil in a large, deep sauté pan over medium-low heat. Hold a fine-mesh strainer over the pan and pour the contents of the blender through the strainer, then discard the solids in the strainer. The sauce should be smooth and creamy, with a consistency similar to Alfredo sauce. If it is too thick, stir in another ¼ to ½ cup broth or water. Taste and add more salt to your liking. Turn the heat down to low, partially cover the pan, and cook, stirring occasionally, for 25 to 30 minutes. Since the mole is fairly thick, it will not come to a simmer.
Meanwhile, preheat the oven to 400°F for the mushrooms.
In a small bowl, combine the oil, oregano, garlic powder, salt, and pepper and mix well.
Lay the whole oyster mushrooms on a rimmed baking sheet and evenly drizzle the oil mixture over the mushrooms, then gently toss with your hands, making sure everything is well coated. Roast for 12 minutes, then flip the mushrooms and roast for an additional 12 minutes, or until golden and crispy.
To serve, add a generous spoonful of mole to each plate, then top with some of the crispy golden mushrooms, garnish with sesame seeds, and enjoy with warm tortillas.