Guajillo chillies can be used for many 'stew' type dishes, but I quite like using them with mushroom. The balance of the two work perfectly and the makes these tacos taste similar, or even better, to their meat equivalent.
Using the tip of the knife, slit each chilli lengthwise. Remove the seeds and membranes, cut off the stem.
Soak the chillies warm water until covered for at least 10 minutes.
Place the chillies in the blender, without the water, and add the tomatoes, garlic and onion. Blend until you achieve a runny and smooth consistency, add water from soaked chillies if needed.
In a large saucepan, add the vegetable oil and bring to medium heat. Add the blender mixture and cook for 5 minutes adding salt and pepper as needed.
Lastly, cut the mushrooms in 2-3 cm slices and add to the saucepan. Reduce the heat to low and cook for 20 minutes.
Warm up your tortillas and fill them up with the mushroom filling.