Roast the chiles over an open flame until the skins are mostly blackened. (I set mine on my stove's burner over a medium-low flame, and turn them occasionally with tongs.) Set aside until cool enough to handle, then peel, seed, and chop the chiles.

Separate the stems from the cilantro leaves and reserve both. Chop the stems and place them with the chiles and zucchini. Reserve the leaves in a separate bowl.

Warm the oil over medium heat in a large saucepan or soup pot. Add the onion and saute until slightly translucent, 5 minutes. Add the chile, cilantro stems, zucchini, parsley, mint and salt. Cook, stirring occasionally, until the zucchini is fairly soft, 5-10 minutes. Add the tortilla and enough water or stock to come up to the level of the vegetables. Increase the heat and bring the soup to a boil, then reduce the heat to medium-low and simmer the soup, partially covered, until the zucchini is very soft, about 15 minutes.

Let the soup cool slightly. Reserve a few pretty sprigs of cilantro for garnish, and add the rest to the soup. Use an immersion blender to puree the soup completely smooth. (Alternately, puree the soup in a blender in two batches.) Add the lime juice to taste, and more salt if needed. If the soup is thick, thin it with a bit more water or stock; if the soup is too thin, you can add more tortilla, simmer for 5 minutes to soften, and puree again.

Heat the remaining oil in a heavy (such as cast iron), medium skillet set over medium-high heat until it shimmers. Add the tortilla strips, and saute, flipping and stirring frequently with a metal spatula, until the tortillas are golden and crisp, reducing the heat if needed. Season with a pinch of salt.

Serve the soup warm, garnished with a dollop of cream, a handful of tortilla strips, and leaf or two of cilantro and mint.