Vegetarian pozole verde

Step 1: If using fresh 1 ⅛ lb tomatillos, put them in a pan with the 2 jalapeño chillies and 1 poblano pepper, cover with water and simmer over a medium heat for 8–10 minutes, until the tomatillos turn from bright to olive green and soften. Stop before they burst, or they turn watery and sour. Lift out and leave to cool slightly; canned tomatillos need no cooking.

Step 2: Meanwhile toast 2 ⅞ oz hulled pumpkin seeds in a dry frying pan over a medium-low heat, stirring all the time, until they puff, smell nutty and start to pop. Tip them straight onto a plate so they don't keep cooking.

Step 3: Pull the stalk and seeds from the poblano. Blend the tomatillos, chillies, pepitas, half of ½ white onion (roughly chopped), 4 cloves garlic, 1 bunch fresh coriander, 4 sprigs epazote and 250 ml of the 1 ¼ cups vegetable stock until completely smooth, at least 1 minute. Taste: it should be tangy, green and grassy, with a clear chilli kick.

Step 4: Heat 3 tbsp vegetable oil in a large heavy pot over a medium-high heat. Add 10 ½ oz oyster mushrooms in one layer and leave them alone for 3 minutes so they brown; stir and cook 3 minutes more, until golden at the edges. Browning gives the soup the savoury depth meat would.

Step 5: Finely chop the other half of ½ white onion, add it to the mushrooms and cook for 3 minutes until soft.

Step 6: Turn the heat to medium and pour in the green sauce; it will spit. Fry it, stirring, for 5 minutes, until it darkens a shade and thickens. Frying the sauce cooks out the raw garlic and onion taste.

Step 7: Add 1 ¾ lb cooked hominy, 14 oz chickpeas, the rest of 5 cups vegetable stock, half of 1 tsp dried Mexican oregano rubbed between your palms, and 1 ½ tsp salt. Bring to a simmer, then cook gently, half covered, for 20 minutes, until the hominy is plump and the broth is creamy. Don't boil hard: the pumpkin seeds can split the broth and dull its colour.

Step 8: Taste and add salt and a squeeze of lime if it needs lifting. Thin with a little water if it has thickened too much; it should coat a spoon but stay soupy.

Step 9: Serve in deep bowls with 7 oz white cabbage, 6 radishes, 1 avocado, 2 limes, 6 corn tostadas and the rest of 1 tsp dried Mexican oregano on the table. It keeps 3 days in the fridge and thickens as it sits; loosen with stock when reheating.