3 tablespoons canola or olive oil
4 garlic cloves, thinly sliced
2 large shallots, thinly sliced
Salt and ground black pepper
700 grams mixed mushrooms, such as maitake, oyster, cremini or shiitake, torn into bite-size pieces
1 to 2 fresh red or green chillies, thinly sliced (or 3/4 teaspoon chilli flakes)
½ cup low-sodium soy sauce, plus more to taste
¼ cup rice wine vinegar, plus more to taste
2 cups herbs (tender leaves and stems), such as coriander, mint, chives, parsley or a mix, for serving
Sesame seeds, sesame oil or both, for serving (optional)
Heat oil in a large, heavy-bottomed pot or Dutch oven over medium heat. Add garlic and shallots and season with salt and pepper. Cook, stirring occasionally until shallots start to turn a nice golden brown, 3 to 4 minutes. Add mushrooms and half the chilli and season with salt and pepper.
Cook, stirring occasionally until mushrooms have softened, released much of their water and turned a deep golden brown, 10 to 15 minutes. (A browned mushroom with have infinitely more flavour than an unbrowned mushroom because the water inside it evaporates and the flavour concentrates. So do not skip this step.)
Add 1/2 cup soy, 1/4 cup vinegar and 8 cups of water. Bring to a gentle simmer and season with salt and pepper. Continue to simmer until the flavours have melded and the broth tastes good enough to drink (you will be drinking it), 15 to 20 minutes. Season with more soy sauce and vinegar as you like.
Meanwhile, cook the noodles in a large pot of salted boiling water until just al dente. (The timing will depend on the type and brand of noodles, so consult the package.) Add noodles to the pot with the broth and let them hang out in there for a minute or two to finish cooking and soak up all that flavour.
To serve this delicious vegan spicy noodle soup, use tongs to divide the noodles and mushroom among bowls, then ladle the hot broth over the top. Serve with the remaining chilli, the herbs and the sesame seeds and oil (if using) for people to dress their own bowls to their liking.