Method

1.  Heat a large saucepan with a lid over a medium heat.
2. Finely chop 1 onion and add to the heated pan with the oil and sauté for 2-3 minutes until softened but not coloured, stirring occasionally with a wooden spoon.
3. Peel the potatoes and cut into bite-sized pieces. Remove the florets from the cauliflower and cut into small florets, which are similar in size to the potatoes.
4. Stir in the cumin, paprika and tumeric into the onion and cook for 1 minute, stirring constantly.
5. Add the potatoes and cauliflower and mix until evenly coated.
6. Pour in 450ml of water and add the tomatoes. Cover with a lid and reduce the heat right now. Simmer gently for 15-20 minutes or until the vegetables are tender.
7. Trim the mushrooms and add to the cooked vegetable mixture with the spinach.
8. If using fish, cut into bite-sized pieces and gently fold into the stew with the prawns.
9. Remember to wash your hands and work surfaces after cutting raw fish. 
10. Simmer for 3-4 minutes untul the fish and prawns are cooked through. Season lightly with salt and pepper and ladle into bowls to serve. Garnish with coriander.