Step 1Place onion, garlic, ginger, chilli, turmeric and cumin in a food processor and blitz until a paste.
Step 2Heat oil in a large heavy-based saucepan over medium heat. Add the curry paste and cook, stirring, for 2–3 minutes, or until fragrant. Add potatoes, carrots and 1 cup of water, and bring to the boil. Reduce heat to low and simmer, covered, for 15 minutes, or until potato is nicely tender.
Step 3Add coconut milk, prawns and zucchini, and simmer, uncovered, for 5 minutes. Stir through the spinach until just wilted. Serve with steamed rice and garnish with extra green chilli.