Wash marrows and scrub sweet potato - chop roughly.
Roughly mince chopped onion, garlic and ginger in food processor. (If you do not have a food processor or chopper, chop very finely with knife).
In a large pot, heat coconut oil and add minced onion, garlic and ginger. Cook for 3-4 minutes, stirring frequently to avoid sticking or burning. Add the curry and cook for 1 minute, until fragrant.
Add the roughly chopped marrows and potatoes to the curry mixture and stir until vegetables are well-coated. You may need to add some of the vegetable stock, if the mixture is too dry.
Lower the heat, cover the pot and sweat the vegetables for 10 minutes, stirring occasionally to prevent sticking.
Pour in the vegetable stock. Shake the canned coconut milk well and add, along with the stock. Give the soup a good stir and cover with a tight-fitting lid.
Bring to the boil, lower the heat to barest minimum and simmer for 25 minutes. Turn off the heat and leave soup to cool for 10-15 minutes.
With a hand blender, process the vegetables until smooth and stir in the ground cashews.
Warm soup gently for a few minutes, stirring in the cashews to blend completely. Season to taste.
Serve piping hot with whole roasted cashews and coriander.
Sweet potatoes are a powerhouse of vitamins and minerals. They're packed with vitamin A (beta-carotene), essential for good vision and to help the immune system. They are also a good source of vitamin C, manganese, copper, pantothenic acid and vitamin B6. Sweet potatoes are also a source of dietary fibre, niacin, phosphorus, vitamins B1 and B2.
Marrows are very low in calories but their nutritional value packs a punch. The peel of the marrow is rich in beta-carotene, a powerful antioxidant which can help prevent free radicals from causing damage to DNA tissue.
Cashews, similar to all other nuts, are a good source of unsaturated fat. Eaten in moderation, nuts and seeds form an essential part of a healthy, plant-based diet.
Coconut milk provides a plant-based protein which is good for you. But both coconut milk and oil contain saturated fats - best you use these in moderation.