Tortilla Soup

Method

1. Stack 2 corn tortillas and cut them into strips about 5 mm wide. Heat the 150 ml of oil in a small deep pan over a medium-high heat until a strip sizzles briskly on contact, then fry the strips in two batches for about 2 minutes each, turning, until golden and rigid. Lift out with a slotted spoon and drain on kitchen paper; salt them lightly while hot.
2. Wipe the seeds and stalks from 2 pasilla chillies. Slide one into the hot oil for 10 seconds only, until it puffs and smells toasty, then drain it on the paper for the garnish. Tear the second chilli into pieces and soak it in just-boiled water for 10 minutes to soften. Take the frying pan off the heat and reserve the oil for another use.
3. Set a dry heavy frying pan or comal over a high heat and char 180 g plum tomatoes, 40 g white onion and 1 clove unpeeled garlic, turning, for 8 minutes, until blistered and blackened in patches. Peel the garlic. Blend the charred vegetables with the drained soaked chilli and a splash of its soaking water to a smooth purée.