Cod Fish Curry

Today there a promotion on cod, fish and as my nutritionist strongly advised to eat healthy (or to try to) I bought a filet which was quite big, but then I won't have to cook for next 2 days. I wanted to make a curry, so thank you Google and thanks to Jamie Oliver's recipe found here I did the following slightly adjusted:
550gr. cod fish (filet)
6 tomatoes
3 white onions
3cm fresh ginger
3 garlic cloves
2 teaspoons mustard seeds
1 teaspoon fennel seeds
2 teaspoons turmeric
1 little green pepper
10 curry leaves
400ml coconut milk
1 red pepper
250gr fresh spinach
5tbs olive oil
salt
Peel the tomatoes and cut them in pieces
Chop the onions
Mash the garlic and grate the ginger
In a wok, heat the oil and put the mustard seeds, when they start crackle add the fennel seeds, ginger, garlic, curry leaves and stir. Then add the onion and simmer for 5 minutes, add the tomatoes, turmeric, red pepper and green little pepper simmer a few minutes. Poor the coconut milk, add the fish, cover and allow to cook for about 5 more minutes. Adjust the seasoning if needed. One minute before serving add the spinach.
Bon appetit !