Blend the drained watercress in a food processor with four ice cubes and two tablespoons of water. Turn the motor off and scrape a spatula down the insides of the food processor at intervals ...

For the aubergine purée and sweet potato, preheat the oven to 200C/180C Fan/Gas 6. Put the aubergines in a roasting tray, sprinkle with the garlic cloves, drizzle with 1 tablespoon oil, season ...