Step 1 Set a large non-stick frying pan over medium heat. Heat rice bran oil. Add mustard seeds and cook, stirring, for 1 minute. Add cumin, turmeric, ginger, chilli and garlic; cook, stirring, for 1 minute.
Step 2 Add sweet potato to frying pan and cook, stirring frequently, for 10 minutes, or until golden. Toss zucchini and cauliflower through mixture; stir in vegetable stock, cover and bring to the boil.
Step 3 Reduce heat to low and cook vegetables for 15–20 minutes, or until tender. Add chickpeas and cook for 5 minutes. Stir chopped coriander through mixture; leave to cool slightly. Transfer spiced vegetables and chickpeas to an airtight container and freeze.
To reheat: Transfer spiced vegies and chickpeas to fridge and leave to thaw for a day (or overnight). Place thawed veg and chickpeas in a shallow microwave-safe dish; cover and microwave on 50% power, stirring every 3 minutes, for 10–12 minutes, or until hot.
To serve: Warm naan breads (or pitas). Divide spiced vegetables and chickpeas among 4 plates; top with coriander sprigs. Serve each dish with half a naan bread (or pita) and mango chutney.