Heat the oil in a frying pan, add the garlic and chilli and cook for 3 minutes. Add the eggplants, banana chilli and sweet potato and cook a few minutes. Add the coconut milk and water, stir through the tamarind paste, fish sauce and lime leaves.
Bring to the boil, lower the heat and simmer gently for 20 minutes or until the vegetables are just tender.
Add the beans, squash, zucchini and asparagus, bring to the boil again, turn down the heat and simmer five minutes.